List of characters in mythology novels by Rick Riordan

This is a list of characters in the Percy Jackson & the Olympians and The Heroes of Olympus series.

Main characters

Percy Jackson

Main article: Percy Jackson

Perseus "Percy" Jackson is the protagonist and narrator of the series, a son of Poseidon. Being a child of the "Big Three" (Zeus, Hades, Poseidon), Percy is the hero referred to within the prophecy of the Oracle, which foretells that the next half-blood child of the "Big Three" to reach the age of sixteen would have to make a decision that would mean the destruction or saving of Olympus. He has hydrokinetic powers that develop throughout the story, becoming strong enough for him to summon a small hurricane in the Last Olympian. Simply being in water can also heal and energize him, water pressure is no limit to him, and he can see underwater at any depth. He can also communicate with equestrian animals (Pegasi, Hippocampi, etc.), since his father created horses from sea foam. He has a sword called Anaklusmos (Riptide) that was a gift from his Father Poseidon, delivered to him by Chiron. It transforms from a common enough-looking ballpoint pen. It is made of celestial bronze and he can never lose it; it will always return to his pocket. He was technically only selected to go on two of the five quests in the series, the first being the retrieval of Zeus' master thunderbolt. In The Battle of the Labyrinth, Percy has to go through the Labyrinth (a big subterranean maze) in order to defend the camp against Luke (a son of Hermes and servant of the Titan lord Kronos). The quest in The Sea of Monsters was actually led by Clarisse (daughter of Ares), but Percy sneaks out of camp because he needs to find Grover, his best friend/protector. In The Titan's Curse, he is also not selected to go on the quest, but he follows the group because he needed to help Annabeth. Percy has a crush on Annabeth, but his love life has been difficult as a result of Aphrodite's promise she made to him when she met him in the desert. After he helps Zoë, Bianca, Grover, and Thalia, Zoë reluctantly allows him to become the fifth member of their team. He takes on the curse of Achilles (invincible in all but one point, which is a point on his back, directly across his navel) and leads the army against Kronos in The Last Olympian. In The Lost Hero, Hera/Juno sends Percy to the Roman Camp as an exchange, with no memories of who he is or where he came from, so that he can learn about them. His time there will most likely be reviewed in The Son of Neptune.

Annabeth Chase

Main article: Annabeth (Percy Jackson)

Annabeth Chase is a daughter of Athena. She is shown to be somewhat pompous at first, but quickly warms to Percy on their first quest together. Being a daughter of Athena, she is very intelligent and has a fascination with architecture. In battle, she is a skilled enough fighter to hold her ground with Percy, and is also by far superior in strategy. She ran away from home when she was seven and met Luke and Thalia, who took her with them to get to Camp Half-Blood. She aids Percy in four of his five quests and is captured in one of them. Though she harbored interest for Luke, she eventually gravitates towards Percy. She kisses him in The Battle of the Labyrinth when he was going into Mt. St. Helens and the telekhines attacking them are distracted. Percy also harbors feelings for her (he gets jealous when she talks about Luke). She is also shown to get jealous over Percy's relationship with Rachel. At the end of the entire series, Percy and Annabeth are together. She owns a Yankee cap that makes the one who wears it invisible, gift from her mother. She fights with a knife that was given to her by Luke. At the end of The Battle of the Labyrinth Daedalus gives her his computer. In The Lost Hero, Annabeth throughout the book is constantly trying to find Percy, organizing search parties and going out trying to find him. She welcomes Piper McLean to Camp Half-Blood, but seems to be distracted.

Grover Underwood

Main article: Grover Underwood

Grover Underwood is a satyr and Percy Jackson's best friend. He has found the four most powerful demigods of the century: Percy Jackson (son of Poseidon), Thalia Grace (daughter of Zeus), and Nico and Bianca di Angelo (children of Hades). Before his death, Pan (the god of nature) proclaims Grover as the bravest satyr ever to be and names Grover as his successor to carry on his word to protect the wilderness. The Council of Cloven Elders is angered by this choice. He is the boyfriend of the tree nymph Juniper.

Tyson

Main article: Tyson (Percy Jackson)

Tyson is a Cyclops, the son of Poseidon and a Nature Spirit. Technically he is not a demigod, but at camp he resides in Percy's cabin, and is considered to be Percy's brother. He first appears in The Sea of Monsters as a homeless boy. He is afraid of Grover while Grover is also afraid of him as Cyclopes and Satyrs are afraid of each other

Nico di Angelo

Nico di Angelo is a son of Hades. At first Percy assumed Hades broke the oath not to have children after World War II, but Nico and his sister Bianca had been placed in the Lotus Casino, where 'time stands still' since before the oath was made. At the time, he took great interest in a game called Mythomagic. Nico has the power to raise undead, shadow travel, and create great fissures in the ground that swallow up anyone or anything unfortunate enough to be standing on it at the time. For a time, he was Percy's enemy, blaming him for the fact that he had failed to protect Bianca as he had promised, but they became friends eventually. Nico tried multiple times to raise his sister from the dead and had difficulty contacting her, even using Happy Meals to raise the dead. Nico refused to stay at Camp Half-Blood in the fourth book after noting that he was not welcomed at Camp Half-Blood; he compares this to the fact that his father is not welcomed at Olympus. Several months later, he informed Percy of a plan that could lead to defeating Kronos. In the final book, he convinced Percy to bathe in the River Styx, making him invincible barring the small of his back.

Thalia Grace

Thalia Grace is a daughter of Zeus. Grover Underwood was assigned to watch over her when she ran away from home at ten years old. On her journey, she met Luke Castellan and Annabeth Chase. They also had brief encounters with the Hunters of Artemis and she was enticed to join by Zoë Nightshade. When she was twelve, they were all soon attacked by a herd of monsters and caught by a Cyclops in New York. She was captured, but thanks to Annabeth, was freed. They escaped, but found that the monsters they had briefly escaped caught up to them. As they reached Half-Blood Hill, Thalia sent Luke, Grover, and Annabeth over the boundary line while she faced the monsters. She sacrificed her life for her friends, and her father, Zeus, took pity on her and transformed her to a pine tree. She is later brought back to life by the Golden Fleece and joins the quest in the third book where she ultimately joins the Hunters, taking the place of Zoë Nightshade. She has a younger brother, Jason Grace who was separated from her when she was 10. This became the reason she ran away from home. She wears a lot of dark makeup and punk style clothing. She has blue eyes and spiky black hair.

Luke Castellan

Luke Castellan is one of Hermes's children and a major antagonist of the series. Though initially the counselor of Cabin 11 and an ally to Percy, he revealed his true nature as a high-ranking member of Kronos's army by attempting to kill Percy at the end of The Lightning Thief, and on several occasions afterward. He is shown to harbor a great bitterness towards the gods (particularly his father, Hermes) for what he regards as abandonment. His mom has been driven crazy because she tried to become the Oracle. After reforming, Kronos possessed Luke's body. However, in his duel with Percy on Mount Olympus, striking Annabeth reminds him of his promise to protect her, temporarily freeing him from Kronos's influence. After Percy makes his choice to give Luke Annabeth's knife, cursed by the broken promise, Luke kills himself by stabbing his own Achilles heel to destroy Kronos, fulfill the prophecy, and become the hero of the war. Luke was an enemy but he died a hero and he fulfilled a prophecy and he was the cause of untimely deaths.

Jason Grace

Main article: Jason Grace

Jason Grace is the son of Jupiter, brother of Thalia Grace, and main protagonist of The Heroes of Olympus series. He is from a Roman Camp Half-Blood that consists of half-bloods born of the Roman aspect. His memory was stolen by the goddess Hera. He and Percy Jackon have exchanged places, because they are the respective leaders at both camps. Jason trys to recall who he is and begins to remember some pieces of his former life.

Piper McLean

Main article: Piper McLean

Piper McLean is the daughter of Aphrodite and friend of Jason. At the beginning of the "Lost Hero" she believes that Jason is her boyfriend due to the mist but she still has feelings for him even when she finds out they aren't in a romantic relationship. She stands up for her friends to bullies like Drew her half-sister. She has a rare ability that many Aphrodite children do not have, charmspeak. Meaning that she can persuade anybody to give her anything or do anything like when she told Jason not to die after he saw Hera's divine form and when she talked a dealer into giving her a BMW.

Leo Valdez

Main article: Leo Valdez

Leo Valdez is the son of Hephaestus and friend of Jason. At the beginning of The Lost Hero he believes that Jason is his best friend due to the mist, but later they do become best friends. Leo also has a rare ability that no other son of Hephaestus has had in four hundred years, fire. Leo can generate fire from his hands allowing him to do much more and he is an excellent mechanic.

Greek/Roman gods

• Zeus/Jupiter: The King of the Gods, God of the Sky, Zeus is brother to Poseidon and Hades, uncle to Percy, father of Thalia, son of Kronos. His Roman counterpart is Jupiter, who has basically the same role, brother to Pluto and Neptune, and father to Jason. He is a principal character in the first book but is a minor one in the next four. His cabin is Cabin #1. Poseidon calls Zeus dramatic, saying that he might do better as the God of the Theater. His symbol of power is his Master Bolt. In "The Lost Hero," Zeus (under the influence of Khione) forbids contact between gods and mortals and closes down Olympus. Despite this, Zeus indirectly aids the demigods several times on their quest, such as answering his son's prayer for aid against Enceladus.
• Hera/Juno: The Queen of the Gods and the Goddess of Marriage. Hera plays a small role in The Titan's Curse but is one of the gods who help Percy and the others in their quest in The Battle of the Labyrinth. At the end of the book, Annabeth and Percy offend her because she did not care that Luke was gone or that Daedalus and Pan were both dead. She especially dislikes Annabeth and curses her like how Ares cursed Percy in the 1st book. She thought Luke, Pan and Daedalus were better off gone. Cabin #2 at Camp Half-Blood is dedicated to her, but is perpetually empty; as the goddess of marriage, she has not given birth to any demigods. In spite of this, Hera meddles with the affairs of many demigods. In The Last Olympian she has a minor role where she congratulates Percy on his victory rather disdainfully and says that she would have to let him and Annabeth live a little longer. Juno returns in The Lost Hero in which Percy Jackson has disappeared. She has been kidnapped by Gaea and contacts Jason Grace, the new protagonist and asks him to help her. It is then revealed that Juno snuck out of Olympus and exchanged Percy and Jason to try and unite the Roman and Greek demigods. She goes against the wishes of Zeus in this regard because she wants to save everyone- gods, demigods and mortals- from the new evil. Juno also admits that she is bitter towards heroes and demigods because she does not have any of her own. Juno, Hera's Roman counterpart, is more warrior-like and more disciplined and rebellious. Juno even states that Hera would not have disobeyed Zeus, but Juno would.
• Aphrodite/Venus: The Goddess of Love, Beauty, Lust, etc. She is mentioned in The Lightning Thief and appears briefly in The Titan's Curse. Her children (mostly girls) live in Cabin #10. She wears a red satin dress and has long dark-brown hair in ringlets, though she sometimes wears it down. Her appearance changes as Percy looks at her, matching every female he has ever had a crush on (one being Annabeth). She encourages Percy to pursue a quest for true love. She is shown to have interest in Percy's feelings towards Annabeth and promises to make Percy's love life hard. She appears again at the Council of the Gods and votes to let Percy live. Being a love-based god she also loves Percy and possibly desires him. Aphrodite is also the last child of Ouranos. Aphrodite is the mother of Piper McLean, a main character in The Lost Hero, and changes her daughter's appearance twice to make her more beautiful.
• Apollo: The God of the Sun. The campers in Cabin #7 are his children. He drives a flying red convertible, a Maserati Spyder, that glows brightly like the sun. He appears to be about 18 or 19 years old and has sandy colored hair and dazzling white teeth. Apollo wears Ray-Ban sunglasses and sports an iPod. Percy notes that he looks similar to Luke, but less evil. He also loves to recite poetry, especially haikus; Percy describes them as so bad that he would rather be shot by an arrow than listen to one, but Zoe says his limerick days were much worse. Apollo helps Percy and his friends by flying them to Camp Half-Blood in The Titan's Curse and later speeding up a train while being disguised as a homeless man. In The Last Olympian, he heals Annabeth's broken arm after she was thrown into her mother's throne. Apollo is also the god of prophecy and controls the Oracle. At the end of the war between the Titans and the gods, Rachel is certified the new Oracle by Apollo. His name is both Greek and Roman.
• Ares/Mars: The God of War and Bloodlust. His children are the campers in Cabin #5. He first encounters Percy in The Lightning Thief. Ares drives a large, black, Harley-Davidson motorcycle with a flame-pattern paint job, a boar themed antenna, handles, boars head shaped red headlight and a leather seat made from human skin. He wears red wraparound sunglasses that cover his eyes, which are flames, a bulletproof vest, combat boots, black leather biker clothes, and a black leather duster. His face is covered with scars from many fights. Once, Ares sends Percy, Grover and Annabeth to retrieve his shield, which he left behind after a date with Aphrodite. They travel to a Tunnel of Love, which ends up being a trap set by Hephaestus. He intercepts Zeus's master bolt from Luke in The Lightning Thief and gives Percy a backpack containing it. He wants to cause discord among Zeus, Poseidon and Hades. Later, he is overpowered by Percy in a duel. He curses Percy that his sword will fail him in battle and departs. Ares returns with minor roles in The Sea of Monsters and The Titan's Curse.
• Artemis/Diana: The Goddess of the Moon, Wild Animals, and the Hunt. She is the twin sister of Apollo. Cabin #8 at Camp Half-Blood is dedicated to her, though it is unoccupied, except for the rare visits when her group of huntresses stays at the camp, such as in The Titan's Curse. She is a maiden goddess, which explains the vacancy of her cabin. She has a prominent role in The Titan's Curse. Artemis appears to be about 12 years old. She has auburn hair and silvery-yellow eyes, the color of the full moon. Artemis leads a group of teenaged girls, the Hunters. The Hunters pledge to give up love in exchange for immortality. The Hunters never grow up and can only die if they are killed in battle or break their oath. Artemis leaves the Hunters to pursue a monster that has the potential to destroy Olympus. She is abducted along with Annabeth by Atlas and is forced to hold up the sky. She is rescued by Percy who holds the sky for her so she can fight Atlas. Artemis and Percy trick Atlas into holding the sky again. Artemis transforms Zoe into a constellation after she is killed in battle. She seems to like Percy, saying that he's okay for a boy, and later refers to him as a man. She speaks up for Percy, Annabeth and Thalia at the Council of the Gods. She votes for Percy to live. Thalia joins her hunt at the end of The Titan's Curse, preventing her from fulfilling the Oracle's prophecy. Artemis did not follow Zeus' order to not have contact with mortals by still communicating with her Hunters. Thalia states, "Artemis follows her own rules," even though she does this without Zeus' knowledge. She sent Thalia to find Jason, her long loss brother.
• Athena/Minerva: The Goddess of Wisdom and Battle Strategy. She first appears in The Titan's Curse, where she is shown to dislike Percy and his relationship with Athena's daughter, Annabeth. Athena is described as being beautiful but also serious and foreboding. She has intense grey eyes, as do almost all of her children who reside in Cabin #6, but has black hair, as depicted in The Demigod Files, unlike most of them, who are blonde. Athena considers Percy to be very dangerous as he has the potential of fulfilling the Prophecy that a child of one of the Big Three will destroy Olympus. She advises Percy that wise counsel is not always the most popular, and cautions him about his fatal flaw. She also votes not to let Percy live. Percy considers Athena one of the most dangerous beings he has encountered, noting that because of her calculating intelligence, her plans rarely fail.
• Demeter/Ceres: The Goddess of the Harvest. She is first mentioned in The Sea of Monsters, when Hermes is talking to Percy about the quest. She was also one of the goddesses who voted to keep Percy alive in The Titan's Curse. Demeter made three brief appearances along with her daughter Persephone in The Last Olympian. Her children reside in Cabin #4.
• Dionysus/Bacchus: The God of Wine and Madness. He is Percy's cousin. He is the director of Camp Half-Blood where he was sent by his father Zeus for chasing an off-limits nymph. At Camp Half Blood, he is known as "Mr. D." He is shown to hate his job and have a low opinion of demigods stemming from Theseus' abandonment of Ariadne, but he has to remain at Camp Half-Blood for another fifty years (his punishment used to be 100 years, then Zeus shortened it). His children live in Cabin #12. He can be seen playing with the satyrs in camp. He appears in all the books. In The Battle of the Labyrinth, he goes out to search for the minor gods and returns at the end of the book. He rarely bothers to call the campers by their proper names, calling Percy Jackson names such as "Peter Johnson", "Perry Johannson", or "Pierre Jorgenson" throughout the series. He also calls Annabeth "Annie Bell" or "that Anne girl", regardless of the fact that she has been in Camp Half-Blood since she was seven years old.
• Hades/Pluto: The God of the Underworld, son of Kronos, Hades is brother to Poseidon and Zeus, and uncle to Percy. He is the husband of his niece Persephone and is Nico and Bianca di Angelo's father. Percy first encounters him in The Lightning Thief on his quest to find and return Zeus's master bolt. In The Last Olympian, Hades traps Percy when Nico leads him to the Underworld palace. He plans to put him in the dungeon until Nico turns sixteen, so Nico can fulfill the prophecy. He appears again with Persephone and Demeter to save Olympus. After the war, Hades, with the minor gods, has a cabin in Camp Half- Blood
• Hephaestus/Vulcan: The Gods' Blacksmith and God of Fire. He appears as a minor character in The Titan's Curse and as a major one in The Battle of the Labyrinth where he helps Percy numerous times. His children reside in Cabin #9. He is the father of Charles Beckendorf and Leo Valdez. He was thrown off of Mount Olympus when he was born because Hera thought he was hideous and wanted a "perfect" family, though Hera denies it. Hephaestus says that Hera likes telling the story that Zeus threw him off the cliff because "It makes her seem more likable." He defied Zeus' rule in The Lost Hero and spoke to his son. He also took the head of Festus to Bunker #9 for Leo.
• Hermes/Mercury: The Messenger of the Gods and the God of travelers, Communication, and Thieves. He has nearly no role in the first book but is a significant character in the second book where he helps Percy by giving him a flask full of air, backpacks, and his special multi-vitamins, hoping that he will be able to rescue his son, Luke, who had joined the Titans. He is also mentioned briefly in The Titan's Curse. He is bitter about Luke's situation and gets angry at Annabeth in The Last Olympian for not saving him when she had the choice. All of his children and the undetermined half-bloods stay in Cabin #11.
• Hestia/Vesta: The Goddess of Hearth and Home. She first appears as a young girl, about 8 years old, who wears a simple brown dress and scarf. Percy sees her when he enters Camp Half-Blood for the first time, but does not speak to her. Percy and Nico encounter her in The Last Olympian when she gives them food. She has glowing eyes that remind Percy of a cozy fire. Hestia tends to the hearth in Olympus while the other gods battle Typhon. Hestia gave up her throne for Dionysus in order to prevent a civil war among the Olympians. She explains to Percy that one of the greatest powers is to yield in order to retain peace. Percy offers Pandora's jar to Hestia, as she is the Last Olympian and Hope survives best at the hearth. Hestia accepts, preventing Percy from being tempted to open it. She later helps Percy when he battles Kronos by making her hearth painfully hot for Kronos when he reaches to get his scythe when it fell into the flames. When Percy looks into her eyes, he can sometimes see the past or the future, like what happened before Annabeth, Thalia and Luke came to Camp Half-Blood.
• Poseidon/Neptune: The God of the Sea, Earthquakes, Storms, and Hurricanes and the creator of the horse. He is Percy's father and his children (Percy's half-siblings) reside in Cabin #3. In the first book, he is suspected of having stolen Zeus's master bolt, but Percy proves the claim false. He appears as a minor character in the next three books. In The Last Olympian, Percy falls unconscious in the ocean and lands at Poseidon's castle. Poseidon is at war with Oceanus, the Titan god of the ocean, and makes Percy go back to camp instead of helping him. He is one of the few gods that does not go and help in the effort to defeat Typhon until Percy tells him that the only way to win is to abandon the sea and fight Typhon. His symbol of power is the three horned trident

Minor gods

• Aeolus: The custodian of the Four Winds. They never made an appearance, but they were mentioned in The Last Olympian. They made it hard for the Titan army to hit Olympus by air. Consequently, it also made it harder for Pegasi to fly. In "The Lost Hero," Aeolus is shown to have gone crazy filling out the Gods' weather requests and wants Zeus to make him a God.
• Amphitrite: The Queen of the Seas, wife of Poseidon, and daughter of Oceanus. In "The Last Olympian," Amphitrite alongside Triton is seen talking strategy with her husband Poseidon in the throne room of their ocean floor palace. Percy Jackson joins them and Amphitrite treats him coldly as he is a reminder of Poseidon's unfaithfulness. Percy expects nothing else and feels sorry for her as she does not have a faithful husband. She is worried how Oceanus is attacking and how Poseidon is losing power to the Titan of the Sea.
• Boreas: The God of the North Wind. In "The Lost Hero," Jason, Piper, and Leo meet him in his palace when they come to him for help.
• Boreads: Calias and Zethes are the sons of Boreas. In "The Lost Hero," they are seen when Jason, Piper, and Leo arrive at Boreas' palace.
• Deimos: The God of Terror and the son of Ares. He appears in Percy Jackson and the Stolen Chariot in The Demigod Files. Deimos and his brother Phobos steal Ares' war chariot from Clarisse. Percy and Clarisse have to get it back to Ares before sunset. On the way, Deimos comes in front of the ferry that Percy and Clarisse are on while riding a sea serpent. He comes back later in the zoo, terrorizing Clarisse by shape-shifting into Ares and yelling at her. Clarisse deduces his true identity and defeats him.
• East River: The minor God of the East River. He only appears in The Last Olympian. He dislikes Percy and the Hudson River. Percy asks him to sink all of the Titan ships that come in his river, and splits the sand dollar his father gave him for his sixteenth birthday with East River and Hudson so they both agree to his request.
• Hebe: The Goddess of Youth. She was mentioned in a few of the books in lists of which minor Gods had turned over to the Titans' side.
• Hecate: The minor Goddess of Magic. Hecate helps Kronos in The Last Olympian by attacking Olympus and making cars stay away from Manhattan. She is the mother of C.C. (Circe), who turns Percy into a guinea pig in The Sea of Monsters. She is the ruler of the empousai, two of which attack Percy in The Battle of the Labyrinth.
• Hudson River: The minor God of the Hudson River. He first appears in The Last Olympian. He dislikes Percy and East River. Percy asks him to sink all of the Titan ships that come in his river, and splits the sand dollar his father gave him for his fifteenth birthday with East River and Hudson so they both agree to his request.
• Hypnos: The God of Sleep and father of Morpheus. In "The Lost Hero," it shown that Hypnos has his own cabin. Clovis is one of Hypnos' sons.
• Iris: The Goddess of Rainbows. She helps people deliver messages through Iris messages. Percy uses Iris messages a lot throughout the series by finding a rainbow and asking Iris to accept his offering. He then throws a golden drachma into the rainbow, says the name of the person he would like to contact and where the person is, and then he can see and talk to the person. Iris specializes in delivering messages through rainbows. She does not appear in the series, but later on gets her own cabin at Camp Half-Blood. In "The Lost Hero," she is revealed to be the mother of Butch. Iris is said to be on good terms with Chiron and Hermes.
• Janus: The God of Gates, Doorways, Beginnings and Endings. He appears as a minor character in The Battle of the Labyrinth where he offers Annabeth a choice between two doors, which represents the situation she was in when she had to make the decision about saving Luke's soul. He has two faces, and each face seems to think the exact opposite of what the other face thinks. He is also mentioned when Percy Jackson has a dream of Deadalus. Janus makes him choose to become a murderer, which he must bear a burden for as long as he lives.
• Khione: The Goddess of Winter and daughter of Boreas who appears in "The Lost Hero." Jason, Piper, and Leo encounter her in Boreas' palace. She ends up betraying them to help Gaia in her conquest.
• Morpheus: The God of Dreams. He appears in The Last Olympian, putting all mortals to sleep in Manhattan before Kronos's army invades Olympus. He also puts Grover to sleep, after he tries to defend the forest of Central Park.
• Melinoe: The Goddess of Ghosts. She lives in the Underworld. Half of her is pale chalky white and the other half is pitch black. She appears in The Demigod Files in the short story Percy Jackson and the Sword of Hades. She scares people by showing them the ghosts of deaths they regret. She shows Thalia her mother and Nico his mother. Percy does not have any ghosts because he has made peace with them.
• Nemesis: The Goddess of Revenge and Balance. She never makes any actual appearances in the books, but she is the mother of Ethan Nakamura who appears in The Battle of the Labyrinth and The Last Olympian. Ethan mentions her in both The Battle of the Labyrinth and The Last Olympian.
• Pan: A Satyr who is the God of the Wild. Satyrs have been looking for him for two thousand years. He appears in The Battle of the Labyrinth. Once Percy and the others find Pan in The Battle of the Labyrinth, Pan dies peacefully.
• Persephone: The Goddess of Springtime and Queen of the Underworld. She is married to Hades. Her parents are Demeter,and Zeus. Hades only allows Persephone to visit her mom in the spring and summer. Unlike most minor Gods, Persephone fights with the Gods during the battle aainst the titans. Persephone appears in The Demigod Files and The Last Olympian. She is notably much kinder and more beautiful in the spring and summer.
• Phobos: The God of Fear and the son of Ares. He appears in Percy Jackson and the Stolen Chariot in The Demigod Files. Phobos and his brother Deimos steal Ares's war chariot from Clarisse. Then Clarisse and Percy have to find it. Phobos has the power of showing people their greatest fears. He shows Percy his greatest fear, which is Camp Half-blood catching on fire and burning, when they are fighting in an aquarium in a zoo. The word "Phobia" was named after him.
• Pompona: The Roman Goddess of Plenty. A statue of her on top of a hotel comes to life in The Last Olympian. She becomes upset with Percy when he thinks she is Demeter. She is also cranky because all of the demigods who walk into the hotel ask her to watch their possessions. She is on the side of the Titans.
• Thanatos: The God of Death. In "The Demigod Files," King Sisyphus made a reference to him when Percy, Nico, and Thalia visit him.
• Triton: The Sea Messenger God and the son of Poseidon and Amphitrite. He is depicted as a merman with two fish tails. In "The Last Olympian," Triton was with his parents talking strategy revolving on Oceanus' war on Poseidon. He is shown to be cold and arrogant to Percy, but respects Tyson.
• Tyche: The Goddess of Fortune. At Camp Half-Blood, her children reside in Cabin 19. According to Rick Riordan's website, Tyche is the most difficult Goddess to find.

Titans

• Aigaios: The Titan of Seas Storms. Like Oceanus, he did not fight in the first war. In "The Titan's Curse," Aigaios was mentioned by Tyson to be assisting Oceanus in protecting the Princess Andromeda from Poseidon.
• Atlas: The Titan General. He is the father of Zoe Nightshade and her sisters, the Hesperides. He was imprisoned in San Francisco upon a mountaintop, forever cursed to uphold the sky. He escaped briefly during The Titan's Curse but was cleverly subdued by Artemis and Percy. He is the father of Calypso and Zoë Nightshade.
• Helios: The Titans of the Sun and son of Hyperion. In "The Titan's Curse," Apollo mentioned that he and Selene faded due to the Romans being too lazy to build their temples and make sacrifices to them.
• Hyperion: The Titan of Burning Light and father of Helios and Selene. He appears only in The Last Olympian in a battle against Percy. Hyperion has a very fiery temper and dresses in full golden armor. He was defeated by Grover Underwood and trapped within a giant maple tree.
• Iapetus: The Titan of Mortalilty, Pain and Death. He accompanies Ethan Nakamura in the Underworld in an attempt to steal the Sword of Hades in The Demigod Files. Percy drags him into the River Lethe and brainwashes him. Percy then tells him he is Bob the Titan.
• Krios: Krios is the Lord of the South and the Titan of Stars and the Constellations. He is only mentioned in one of Percy's dreams, where he is forced to babysit Atlas. He is dissatisfied with his condition because he only wears ram horns, but Hyperion can blow up into flame. He is also mentioned fleeing when Kronos was defeated. He wears armor that has glowing stars on it. In The Lost Hero, Jason mentions that he defeated Krios with his bare hands.
• Kronos: The Lord of the Titans and the main antagonist of the first series. He is the father of Zeus, Poseidon, and Hades, Chiron, and grandfather of Percy. He tries to get Percy to join him and fight against the Olympians. His weapon is a scythe, a "six-foot-long blade curved like a crescent moon" as said in The Battle of the Labyrinth. It is hinted in the book that it is Luke's old sword Backbiter remade into the scythe. He is the father of the "Big Three," which are Zeus, Poseidon, and Hades. He is also the father of Demeter, Hera, Chiron and Hestia. He was sent to Tartarus by his sons and is reforming in The Sea of Monsters, The Titan's Curse, and The Battle of the Labyrinth. When he eventually reforms himself, he takes Luke as his host body. The only reason Luke was not killed during this was because he bore the Curse of Achilles, by being dipped in the River Styx. In The Battle of the Labyrinth, Kronos is delayed to attack Camp Half-Blood. In the fifth book, Kronos leads the Titans to Olympus while the gods were fighting with Typhon. Later, Annabeth and Percy save Luke, and Luke commits suicide to defeat Kronos.
• Oceanus: The Titan of the Ocean. In this series, Oceanus is often depicted as having the upper body of a muscular man with a long beard and horns (often represented as the claws of a crab), and the lower torso of a serpent. He did not fight the Olympians in the first war, but in The Last Olympian, he joins Kronos and is at war with Poseidon. Oceanus joins the side that he thinks will win. After it becomes clear that Kronos had lost the battle, he stops fighting Poseidon and escapes back to the depths of the ocean.
• Prometheus: The Titan of Forethought (and as Grover says, "Crafty Counsel", with emphasis on "Crafty"). He appeared in The Last Olympian, where he gives Percy Pandora's Box (or Pandora's pithos) which contains the spirit Hope. He fought with Olympians in the first war, then switched sides in the second war because he was sure the Titans would win. He is otherwise neutral, as he always tries to pick the winning side. After Kronos was defeated, he is mentioned to have run away and has sent a list of excuses to the Big Three.
• Selene: The Titan of the Moon and daughter of Hyperion. In "The Titan's Curse," Apollo mentioned that she and Helios faded due to the Romans being too lazy to build their temples and make sacrifices to them.

Giants

• Enceladus: A Giant who was the first to be awakened in The Lost Hero. He was killed when Jason and Jupiter threw lightning at him.
• Porphyrion: A Giant who was the first to be awakened in The Lost Hero. He fought Jason and his friends and was teleported away before Hera could finish him off.

Immortals

• Calypso: Calypso first appears in book four. She nurses Percy back to health on her island. She is shown to be in love with Percy, and is heartbroken when he leaves. She is cursed with this as punishment because she supported her father, Atlas, the Titans in the first war. Near the end of The Last Olympian, she is freed from her punishment as part of Percy's wish. She is immortal and lives on an island that makes anyone who lives there immortal for the time of their stay, though once they leave they can never come back.
• Charon: Charon is the Underworld carrier through the River Styx. Percy and his friends meet him in The Lightning Thief.
• Chiron: In the series, he plays the part of the mentor and activities director to the main protagonist Percy Jackson and the other demigods residing at Camp Half-Blood. In the first book, he appears under the pseudonym of Mr. Brunner. Later, it is revealed that he is the son of Kronos. Chiron is a centaur; his horse half is a white stallion.
• Eurytion: A worker of Geryon and the owner of Orthrus. He is usually seen with a huge club. He is a son of Ares. He is unenthusiastic about and later rebellious against working for Geryon. When Geryon is defeated, he starts planning to take over the Triple G ranch. He gives Annabeth a mechanical spider to find Hephaestus.
• Phoebe: The best tracker of Artemis' hunters. She hit the Stoll brothers with arrows in a game of Capture the Flag. She was supposed to go on the quest inThe Titan's Curse, but the Stoll brothers (at the request of Aphrodite) gave her a poisoned (but non-lethal) shirt that prevented her from going. Percy ended up replacing her. She appears in The Lost Hero. The incident with the Stolls appears to have had a lasting effect on her; she appears to think that every boy wants to play a prank on her.
• Zoë Nightshade: The lead Huntress of Artemis. She is a daughter of the Titan General Atlas and the sea goddess Pleione. Percy later discovers she made his magic blade, Riptide. She uses a hunting knife and a bow as her weapons. She is a former Hesperide. but was blotted from history for aiding the half-blood Hercules in slipping past the dragon Ladon and obtaining a golden apple. Ultimately, a combination of Ladon's poison and her father's attacks kill her. In remembrance of her sacrifice, Artemis turns her into a constellation, "The Huntress."

Demigods

• Bianca di Angelo: A daughter of Hades, Percy's cousin and later, a Huntress of Artemis. After Artemis is kidnapped in The Titan's Curse, she undertakes the quest to rescue her alongside Percy Jackson, Grover, Thalia Grace, and Zoë Nightshade. She sacrifices herself to destroy a defunct prototype of Talos because she stole an item from the Junkyard of the Gods. The item she saved was a statue of Hades. Nico di Angelo blames Percy for her death and harbors hard feelings for him for a while afterward. Nico also throws away the Hades statue that Bianca saved when she died. Later, Nico realizes that Hades is their father and that Maria di Angelo was their mother.
• Butch: The demigod son of Iris who first appears in The Lost Hero. He is the counselor of the Iris Cabin. It is said he is the best equestrian at camp.
• Castor: The son of Dionysus and the twin brother of Pollux. Castor died at age 17 during the Battle of the Labyrinth.
• Charlie Beckendorf: A son of Hephaestus, known to be able to build almost anything. He is lead counselor for Cabin 9. He had a minor role in the first four books in the series, but has a larger role in The Last Olympian. He has a crush on Silena Beauregard, whom he starts dating from the short story The Bronze Dragon contained in The Demigod Files. Most members of Camp Half-Blood call him by his surname, Beckendorf. He sacrifices himself at the beginning of The Last Olympian to destroy the Princess Andromeda, a ship that was Kronos' headquarters, unaware that it was actually because of Silena (a spy on the camp) that he lost his life.
• Christopher: The demigod son of Hephaestus who first appears in The Lost Hero.
• Chris Rodriguez: A half-blood son of Hermes (as shown in "Percy Jackson and The Olympians The Ultimate Guide") who had gone to Kronos's side until having gone completely insane in the Labyrinth. Clarisse finds him and brings him to camp where Dionysus makes him sane again. He later has a relationship with Clarisse.
• Clarisse La Rue: One of the children of Ares and the head of Cabin #5. She is hot-tempered, arrogant, big, tall, strong, and is known to dislike Percy. Despite her brash nature, she is capable of compassion, shown when she cares for Chris Rodriguez, a half-blood who became a traitor and was later found crazed and stumbling within the Labyrinth during his bout of madness. She is later seen holding Chris's hand at a campfire after Dionysus cures him of his madness. She later befriends Silena Beauregard, apparently after Silena gives her advice on her first boyfriend. She and her cabin later fight with the Apollo cabin because of a flying chariot. She and her cabin later do not join in the battle of Manhattan because of the chariot, though Michael Yew gives it to them. Silena later impersonates her to bring the Ares cabin into the battle by taking her armor and spear. When Silena is killed by a drakon while she leads the cabin into fighting. Clarisse then grabs her spear back, runs up the drakon and stabs its eye, fully blinding it (Percy already blinded the other eye). The spear then breaks, electrocuting, and killing, the drakon. She then runs at Kronos's armies, appearing to be as invulnerable as Percy, even though she does not have the Curse of Achilles. Percy recognizes that an aura around her highly resembles that of Ares when Percy fought him. Thalia remarks that it is a blessing of Ares and that she has never seen it before in person. She is later frozen by a giant, and, after thawing, is welcomed to Olympus by her father, who is very proud of her.
• Clovis: The demigod son of Hypnos who first appears in The Lost Hero. He is the counselor of the Hypnos Cabin.
• Connor Stoll: One of the children of Hermes. He is brothers to Travis Stoll. Both are known to be crafty and mischievous. He and his brother's shenanigans incapacitated a member of Artemis's Huntresses, which enabled Percy to join the quest of The Titan's Curse. He and his brother have a larger role in The Last Olympian and both survive. He and his brother head Cabin 11 after Luke goes over to Kronos.
• Drew: A demigod daughter of Aphrodite who first appeared in The Lost Hero. She was the Cabin counselor after Silena, but was forced down by Piper McLean. She is vain and sarastic, and can also charmspeak.
• Ethan Nakamura: A son of Nemesis who feels that his mother is unappreciated and fights for her. She took his eye in return for the promise that Ethan would change the world. He turned to Kronos' side after Percy saved his life by letting him live after a duel. After the duel, he pledges himself to Kronos, the last half blood needed for his resurrection. In The Last Olympian, he tries to stab Percy in the small of his back (his Achilles spot), but Annabeth leaps in front of the dagger, and Kronos believes that he tried to stab Percy's Achilles spot. He is in the truce party along with the Empousa queen and Prometheus. Ethan later figures out that the small of Percy's back was his Achilles spot, but instead of killing him, he tries to kill Kronos. Kronos laughs, and kills him easily. Ethan's last words were "Deserve better...if they the minor gods just...had thrones..."
• Harley: A demigod son of Hephaestus who first appeared in The Lost Hero.
• Jake Mason: A son of Hephaestus. He becomes the head of Hephaestus' cabin after the death of Charles Beckendorf in The Last Olympian. He fights in the war between the gods and Titans. He later steps down and gives the role to Leo. In The Lost Hero, he was seen in a body cast after trying to catch Festus. He resigned after Festus led Leo to Bunker 9.
• Katie Gardner: A daughter of Demeter and is and no longer the head counselor for cabin four at Camp Half-Blood as seen in The Last Olympian. Miranda Gardiner is her deputy taking over. She takes over in winter because Katie is not a year-rounder. She fights in and survives the war between the god and the titans. She strongly dislikes Connor and Travis Stoll, because they once put chocolate Easter bunnies on the Demeter cabin's grass roof. She is cousin to Percy Jackson, Thalia Grace, Nico di Angelo and Bianca di Angelo.
• Lee Fletcher: A son of Apollo. He was the original head of Cabin 7 before he was killed in The Battle of the Labyrinth.
• Lou Ellen: Daughter of Hecate, who was first mentioned in The Lost Hero. She is known for playing magical tricks on fellow campers.
• Malcolm: A son of Athena. He is the assistant counselor of the Athena cabin. He leads Athena's cabin to a bridge or tunnel in The Last Olympian. His last name is never revealed. He walks in on Percy and Annabeth hugging in The Battle of The Labyrinth.
• Mark: A son of Ares. He is mentioned by Percy once in The Demigod Files in the short story Percy Jackson and the Stolen Chariot when Percy asks Clarisse which of her brothers played a prank on her. He may have been the one that Percy awoke from a midday nap in The Titan's Curse.
• Michael Yew: A son of Apollo. He is the leader of the Apollo Cabin after Lee Fletcher died in The Battle of the Labyrinth. He is described as very short, four foot six, with personality that makes up for his height, and a face that reminds Percy of a ferret.In The Demigod Files, in an interview with Clarisse, she mentions that she would want to pulverize Micheal.Thus stating, that they are both enemies. Percy finds that very interesting that he's the counselor. He is supposedly killed leading a group of demigods in the fight against Kronos' army. Percy looked everywhere for him, but only found his bow. He is presumed deceased, although this was never confirmed.
• Miranda Gardiner: Miranda is a daughter of Demeter who first appears in The Lost Hero and is the counselor of her cabin. Miranda had her nose (temporarily) removed by Lou Ellen, a daughter of Hecate.
• Nyssa: Demigod daughter of Hephaestus.
• Pollux: The son of Dionysus and the twin brother of Castor. He and his brother are described as blond, athletic, plump faced and good looking. He fights and survives the war between the Titans and the Gods, making his father secretly happy.
• Silena Beauregard: A daughter of Aphrodite and the head of Cabin 10. Percy regards her as one of the nicer girls of the cabin and acknowledges that she is pretty, but still finds her to be a "neat freak". She participates in the Battle of the Labyrinth. She does not think that she is a good fighter and feels that she does not do anyone any good at camp. She unveils her hatred towards the hunters of Artemis, who say that love is worthless, to which she responds by stating that she is going to "pulverize" them. Silena is killed by a drakon when she fights it while pretending to be Clarisse in The Last Olympian. It is also revealed in The Last Olympian that she was the spy giving Kronos information about what was going on at Camp Half-Blood, though when the Stoll brothers ask Percy about it, he will not let Silena be remembered that way. She did, however, want to stop being the spy when her boyfriend Charles Beckendorf died (charming her with his looks, Luke had promised that fewer lives would be lost and that Charles would be safe), but was blackmailed by Luke, when he threatened to reveal her betrayal. This causes Silena to become even weaker or as Percy described, "She looked like glass. Like she was going to break at any time." Percy also notes that no one says the word "spy" during the burning of her shroud ( her shroud is hot pink with an electric spear embroidered on it).
• Sherman: A son of Ares. He, like Mark (another son of Ares), is mentioned by Percy in The Demigod Files in the short story Percy Jackson and the Stolen Chariot, when Percy asks Clarisse which of her brothers played a prank on her. He also may have been the one that Percy awoke from a midday nap in The Titan's Curse.
• Travis Stoll: One of the children of Hermes. He and his brother become the new counselors of cabin 11 after Luke went to Kronos. Travis is the older brother of Connor Stoll. Both are known to be crafty and mischievous. Percy finds it ironic that their last name is Stoll, like the word 'stole'. His and his brother's shenanigans incapacitated a member of Artemis's Huntresses, which enabled Percy to join the quest of The Titan's Curse. He and his brother have a larger role in The Last Olympian and both survive.
• Will Solace: He is a son of Apollo whom Percy took to heal Annabeth in The Last Olympian and become the leader of the Apollo Cabin as seen in The Lost Hero.

Mythological Characters

Some of the known characters of Greek Mythology have made an appearance in this series:

• Achilles: The spirit of Achilles appears briefly in The Last Olympian, warning Percy about The Curse of Achilles.
• Ariadne: Ariadne once helped Theseus when it came to him slaying the Minotaur. When Theseus unknowingly left Ariadne on an island, she was found by Dionysus who took her on as his wife. Theseus "abandoning" Ariadne was one of the reasons why Dionysus dislikes heroes. Ariadne made an appearance at the end of "The Titan's Curse" where she was walking arm to arm with Dionysus.
• Circe: Circe ran a magical beauty boutique in the Sea of Monsters. She was glamorous and went by the alias of C.C. While she treated females at her spa, she turned males into guinea pigs. When Percy was turned into a guinea pig, Annabeth managed to use Hermes' multivitamins to become immune to Circe's spells and escaped with the guinea pigs. Not knowing which one is Percy, Annabeth fed them all multivitamins restoring Circe's victims to normal.
• Daedalus: Inventor of the Labyrinth, son of Athena, and father of Icarus. Daedalus killed his nephew Perdix and took his notes, which he then used to cast his animus (soul) into automatons after Athena branded him with the murderer's hand. He originally owned a hellhound named Mrs. O'Leary and fights the Titan army toward the end of the fourth book. He later decides that it is time to go to the Underworld and leaves Annabeth his laptop which is filled with his notes and ideas. Nico unleashes Daedalus' spirit which destroys the labyrinth. When in the Underworld, King Minos tried to convince the other judges to punish him and fails. Daedalus' spirit now works as the Underworld's architect while being able to visit Icarus and Perdix on weekends.
• The Fates: The three women who control the threads of life.
  • Clotho: The Fate who spins the Thread of Life.
  • Lachesis: The Fate who measures the Thread of Life. In "The Lightning Thief," Percy and Grover encounter them at an old-fashioned fruit stand. In "The Last Olympian," the Fates take Luke's dead body away after the Second Olympian War.
  • Atropos: The Fate who cuts the Thread of Life.
• Gaea: The embodiment of Earth, the mother of the Titans, Giants, and Antaeus, and grandmother of the Olympian Gods. She serves as the primary antagonist of The Heroes of Olympus series.
• King Lycaon: King Lycaon was a king who was turned into a wolf after doing deadly tests on Zeus. In "The Lost Hero," King Lycaon appears where he meets Jason, Leo, and Piper in their search for Aeolus. He was instructed to kidnap Jason and kill Leo and Piper. King Lycaon escaped when the Hunters of Artemis stopped him.
• King Midas: King Midas was a king who had the Golden Touch. He was referenced in "The Battle of the Labyrinth" where he states that Rachael's gold appearance made her look like she was touched by King Midas. In "The Lost Hero" King Midas was among the dead people brought back to life when the Doors of Death opened in Omaha, Nebraska. When Jason, Piper, and Leo arrived at Midas' mansion, he was polite. Midas told them that it was a silly story that he learned his lesson when he touched his daughter, turning her into solid gold. Midas touched Piper's backpack, turning it into flexible gold and making it magic, proving he still had the magic touch. Midas admitted that he had sometimes pat his son Lityerses on the pack accidentally, but he always had the lake to rinse it off. Midas finally revealed he was working for the Giants and turned Leo and Piper into gold. He gave Jason a choice: turn into a nice gold statue for is collection or fight Lityerses and die. Jason fought Lityerses and Midas. Midas and his son fought off the Hunters of Artemis before Jason managed to defeat Lityerses and unfreeze his victims, Piper and Leo.
• King Minos: King Minos is a ghost who is one of the Judges of the Underworld. Nico summons in book four where he pretends to advise him on how to bring Bianca back from the dead he is when really trying to bring himself back. He is also seen as a live king in Percy's dreams/flashbacks. Near the end of the book, it is revealed that he is serving his own dark purpose when he kidnaps Nico and tries to kill Deadalus and use his soul as ransom. When Daedalus ends up in the Underworld following his sacrifice, King Minos tried to convince the other two judges to punish him and fails.
• King Sisyphus: A former ruler of Corinth. He had committed violations of guest hospitality, seduced his niece, stole the throne from his brother Salmoneus, and betrayed Zeus' secrets with one of them telling the River God Asopus where Zeus had his daughter. His major crimes involved cheating death twice. The first where he tricked Thanatos into showing him how the chains worked causing Thanatos to be trapped until Ares freed him (Thanatos being trapped displeased Ares since no one in battle could die). The second time was when he complained to Persephone that his wife Merope did not give him a proper funeral and sent Sisyphus' spirit to the living. Even when Sisyphus did not want to return to the Underworld, he was forcefully dragged back there by Hermes. His punishment in The Fields of Punishment was to roll a boulder up a hill, and whenever he failed he would be tempted to try again. He appears in The Demigod Files in the story titled The Sword of Hades when Percy and Nico ask him advice while Thalia rolls the boulder up the hill. He does not really help them much, but he does say that he helped someone else. He said that he told that other person to go see Melinoe. Therefore, Percy and his friends go to see Melinoe as Sisyphus begs for them to set him free from his punishment as being here was a minor set-back.
• King Tantalus: Tantalus is a spirit from the Fields of Punishment who is the son of Zeus. He ended up there after killing his son Pelops, cutting him up, and serving him as food to the Gods. His punishment in the Fields of Punishment was to stand under a fruit tree in the middle of a lake where the branches and water would go out of reach from him. becomes the activities director at Camp Half-Blood after Chiron is fired. He appears in The Sea of Monsters as a minor character. Even when hired as the activities director, he could not eat or drink as the food kept evading him. He is shown to hate Percy and his friends even more than he hates most half-bloods, yet shows favoritism to Clarisse, such as naming her hero when the camp was attacked by Colchis Bulls, or when she wins the chariot race. He throws a banquet in her honor. When the camp is attacked by a large flock of Stymphalian birds, Tantalus blames it on Percy, Annabeth, and Tyson's "bad chariot driving", despite that they were the ones who defeated the birds. When Tyson is brought to camp, Tantalus insults and makes fun of him even when Tyson is claimed by Poseidon. When at the end of the book, his curse is lifted by Dionysus just before he is sent back to the Underworld as he attempts to take some food along. Though none of the campers were sad to see him go.
• Lityerses: Lityerses is the son of King Midas. In "The Lost Hero," he appeared alongside his father.
• Medea: A sorceress and granddaughter of Helios that Jason, Piper, and Leo encountered in "The Lost Hero." She is shown as the head of a mall in Chicago that Jason, Piper, and Leo visit. She begins to show the demigods her stock of magic objects and potions, but becomes angry when she hears Jason's name (as he is named after the hero that betrayed her). It quickly becomes evident to Piper that Medea is an agent of Gaia, and the one who Hera had warned them about. Jason and Leo however are entranced by the magic in Medea's voice who tells them to attack and kill one another. Piper managed to bring the two to their senses and they blew up the mall. Medea shouts that she will not be abandoned again causing the three to quickly leave before she makes another attempt to destroy them.
• Oracle of Delphi: Apollo's Oracle of Delphi used to reside in the mummified remains of its host until its spirit was transferred to Rachel Elizabeth Dare in The Last Olympian. The Oracle's spirit originally passed from the deceased oracle to a newly chosen oracle; however, at the end of the second world war, the oracle gave a Great Prophecy predicting a child of the Big Three (Zeus, Poseidon, and Hades) would determine whether or not the gods would be preserved or destroyed. Using this information, the Big Three entered a pact in which none could continue to sire heroes. Before this, Hades bore two young children, Nico di Angelo and Bianca di Angelo. Zeus, fearing that either were the children of the prophecy, destroyed the hotel where the di Angelos lived with his master bolt, killing Maria di Angelo, Hades' lover. In revenge, Hades cursed the Oracle to ensure that the spirit of the Oracle of Delphi would not pass to a new host but be trapped inside the body after the death of its host in hopes that it would soon return to the dust along with its bodily prison. After the Battle of Manhattan in which Hades and Nico successfully assist in the defense of Mount Olympus, Zeus honors the Lord of the Dead. In response to his newfound respect from the other gods, he lifts the curse, allowing the Oracle's spirit to pass on into Rachel Elizabeth Dare, effectively releasing the trapped soul of the last host of the Oracle.
• Procrustes: He is depicted as "Crusty," the owner of a Los Angeles mattress store who appears in The Lightning Thief. He trapped Annabeth and Grover on his bed, but he was defeated by Percy.
• Silenus: Silenus is a minor character, appearing in books four and five. He is the leader of the Council of Cloven Elders and is shown to hate Grover, calling him an "outcast" and a "liar". that he has suspicions that he is a spy.
• Theseus: When Nico was trying to summon the spirit of Bianca in "The Battle of the Labyrinth," he ended up summoning the spirit of Theseus.

Creatures and Monsters

• Antaeus: A half-giant who is the son of Poseidon and Gaea. He remained strong while he was on the ground. Percy managed to find a way to get him into the air and defeat him.
• Argus: Argus is a multi-eyed humanoid who works as a security guard at Camp Half-Blood. He is said to have an eye on this tongue which is why Argus does not talk much.
• Automaton: Automatons are like robots, but more highly developed. They have an intricate circuitry in them which makes them hard to fix. Most are made out of normal steel but some like the Bronze dragon are made out of celestial bronze. According to Annabeth, some Automatons in Manhattan were used to either attack or help defend Mount Olympus.
• Bear Twins: Agrius and Oreius are humanoid bears that were a result of a union between a woman and a bear due to the magics of Aphrodite. The two served as Luke's henchmen in The Sea of Monsters.
• Bronze Dragon (Festus): A dragon made of bronze that created by the campers in Hephaestus' cabin to help defend Camp Half-Blood. He is later named "Festus" by Leo Valdez, a son of Hephaestus in The Lost Hero, the first book of the sequel series to Percy Jackson and the Olympians, The Heroes of Olympus.He is also shown in The Bronze Dragon of The Demigod Files .
• Centaur: Half man, half horse. Chiron is a centaur.
  • Party Ponies: They are Chiron's kin. As their name suggests, they are a vast clan-like extended family of rowdy centaurs who reside in the United States with chapters hailing from each respective state. They are key players in two major incidents in the series. In The Sea of Monsters, they along with Chiron rescue Percy from Luke during their duel on the Princess Andromeda. In The Last Olympian, they help Chiron and the others fight the major battle between the Gods and the Titans.
• Cerberus: The three-headed dog who guards the Underworld entrance to the living. In The Lightning Thief, he befriends Annabeth. He also appears in The Last Olympian when he is playing with Mrs. O'Leary. He is the son of Echidna and Typhon.
• Charybdis: One of the two monsters (the other being Scylla) that live on either side of a narrow channel of water. She takes the form of a giant mouth that swallows and releases water, creating whirlpools.
• Chimera: A three-headed beast that is part lion, part goat, and has a snake-headed tail. It is first seen in the form of a Chihuahua. It confronted Percy atop the St. Louis Arch alongside its mother, Echidna. Overwhelmed by the creature and poisoned by its snake head, Percy was forced to jump into the water far below to escape it. It disappeared after Percy dove into the water.
• Clazmonian Sow: A flying pig that appeared directly after Hyperion was defeated. Percy defeats it with the help of Blackjack, a statue of Hermes, and the New York Public Library's two stone lion statues.
• Colchis Bull: An elephant-sized, fire-breathing bronze bull created by Hephaestus. Their horns are silver and their eyes are rubies. In The Sea of Monsters, a bunch of them attacked Camp Half-Blood and are defeated by Tyson. They were later used to make the tracks for the Chariot Race.
• Cyclops: One eyed-giants who have three species as mentioned in The Lost Hero. The first are the elder cyclops, who are friendly, and help the gods, Tyson is one of them. The second is the southern species, who raise Goats and live in caves. Polyphemus is one of them. The third, introduced in The Lost Hero, is the northern group, who helped the Titans make weapons. Ma Gasket is one of them.
  • Ma Gasket: A female cyclops who is the mother of Sump and Torque. She appears in "The Lost Hero" when Jason, Piper, and Leo visit her factory in Detroit.
  • Polyphemus: Percy Jackson and his friends encounter him on an island in "The Sea of Monsters." He is shown to be blind and there was also a reference about Odysseus being responsible for blinding him under the alias of "Nobody."
  • Sump: The son of Ma Gasket who appears in "The Lost Hero".
  • Torque: The son of Ma Gasket who appears in "The Lost Hero."
• Draco Aionius: A bunch of these monsters attacked Camp Half-Blood while Percy Jackson was at the Sea of Monsters.
• Drakon: A race of giant, millennium-old, serpent-like dragons.
  • Lydian Drakon: The oldest and most fiercest of the Drakons. Kronos unleashed it upon Manhattan where it killed many half-bloods before being killed by Clarisse La Rue.
  • Aitheopian Drakon : One was being raised by Luke in The Sea of Monsters. When one of the Bear Twins seemed stubborn on doing a job, Luke threatened him to been fed to the Drakon.
• Echidna: Part woman, part snake. She is the wife of Typhon and the mother of Cerberus, Chimera, Hydra, Nemean Lion, and Ladon as well as several others not in the series. She is first seen as an old lady that owned the chihuahua that was actually Chimera in disguise. She assisted Chimera in fighting Percy at the top of the St. Louis Arch. Disappeared after Percy dove into the water.
• Empousai: Seductive shape-shifting beast women who are similar in appearance to vampires with both shaggy donkey legs and bronze legs. Two Empusa named Tammi and Kelli, pose as cheerleaders in The Battle of the Labyrinth. In The Last Olympian, the Empousa queen appears as part of the truce party along with Prometheus and Ethan Nakumura.
• Erymanthian Boar: A giant boar sent by Pan. Percy, Thalia, Zoë, Grover and Bianca first encounter it in Cloudcroft, New Mexico. Grover is the first to identify it and its potential utility to the team as a form of transportation.
• Feather-Shooting Bird: A type of large black bird that shoots it's feathers like arrows. In "The Demigod Files," Phobos summons them to fight Clarisse after he steals Ares' war chariot.
• Fire-Breathing Horse: A fire-breathing horse that is sold at the Triple G Ranch for war purposes. Some are shown to pull Ares' war chariot.
• Flesh-Eating Horse: A bunch of them are seen at the Triple G Ranch. Some of them tried to eat Percy while he was cleaning the stables.
• Flesh-Eating Sheep: A bunch of carnivorous sheep that are owned by Polyphemus. They help to guard the Golden Fleece. They are as big as a hippopotamus and attack like piranhas.
• The Furies: The Furies are Hades' chief servants and torturers—therefore, they personally searched for Hades's Helm of Darkness, thinking that Percy had stolen it.
  • Alecto: Alecto acted as Percy's pre-algebra teacher Mrs. Dodds in the first book. She is Hades's main servant.
  • Megaera: A Fury that represents grudging.
  • Tisiphone: A Fury that represents avenged murder.
• Gegeines: A race of six-armed giants that appear in The Lost Hero. They are summoned by Enceladus to fight Jason, Piper, and Leo.
• Geryon: In "The Battle of the Labyrinth," he is the owner of Triple G Ranch. Orthrus is guarding the ranch. He gave Percy an impossible task. To clean out the stables of carnivorous horses (one of the tasks Hercules also did). Once Jackson completed the task, Geryon went back on his deal to let his friends free and the two fought. Jackson found Geryon a worthy battle as he was a challenge due to his three hearts which allowed him to be almost impossible to defeat. Jackson defeated Geryon with a well placed arrow (thanks to Hera) that went through Geryon's sides hitting all three hearts at once killing Geryon.
• Giant Badger: A giant badger. In "The Last Olympian," it was mentioned that Gleeson Hedge tried to fend off the Giant Badgers and tried to summon Pan to help him in that.
• Giant Crab: A giant crab that might be Cancer. Percy fought it in the Princess Andromeda during his mission with Charlie. He defeated it by stabbing the soft tissue in its belly.
• Giant Scorpion: A giant-sized scorpion. Native to desert regions, the giant scorpion may be a descendant of the Brontoscorpio, a species of prehistoric aquatic scorpions from Paleozoic times. Daedalus in the alias of Quintus ordered some Giant Scorpions from Triple G Ranch. He kept them in their boxes in the Sword Fighting Arena. He eventually let them out in the camp's forest for a game.
• Giant Squid: A giant squid that might be the Kraken. It was among the sea monsters in Oceanus' army.
• Harpy: Aello ("storm swift"), Celaeno ("the dark") — also known as Podarge ("fleet-foot") — and Ocypete ("the swift wing") are the three harpies were created by Zeus. They work in Camp Half-Blood as "the cleaning harpies" being allowed to eat any camper who stays in camp past noon in the last day of the summer. The Harpies also cleaned the dishes with super-hot lava and are also good in mid-town traffic.|
• Hekatonkheires: Hundred-Handed Ones; giants of incredible strength, superior even to the Cyclopes. They are taller than mountains. The last one, Briares, was imprisoned by Kampê in the fourth book. There was also mentionings that his brothers Cottus and Gyges have faded due to people forgetting about them. When Tyson finds that Briares is too afraid to escape, he is heartbroken. At the end, Briares returns helps defeat Luke and the Titans. In The Last Olympian, Percy sees Briares helping Poseidon defeat the forces of Oceanus.
  • Briares: He first appears in The Battle of the Labyrinth when Percy, Annabeth, Tyson, and Grover rescue him from Alcatraz, where he is being held prisoner by Kampê. Briares is one of the three Hecatonchires ("the Hundred-Handed Ones"), elder brothers to the Cyclopes. His siblings are Kottos and Gyes. Like all other Hundred-Handed Ones, he has fifty different "faces" indicative of his moods. He is very frightened and timid due to his years of imprisonment and feels that he is of no use. Because of this, he runs away from Percy and his companions in the maze-like Labyrinth. However, Daedalus finds him and they both show up to fight for the Olympians in the battle at Camp Half-Blood at the end of The Battle of the Labyrinth. Briares seizes the chance to bury Kampê under a pile of rocks. At the end of The Battle of the Labyrinth, he goes to help the Cyclopes in Poseidon's forge. In The Last Olympian, Briares is shown fighting alongside Poseidon.
• Hellhounds: Hellhounds are a main part of Luke's army and monsters in general. They are described as very large black dogs that have fire glowing in their eyes. They were also mentioned to reside in the Fields of Punishment. Daedalus owns a hellhound named Mrs. O'Leary, who, unlike her relatives, is loving and loyal.
  • Mrs. O'Leary: Mrs. O'Leary is the only friendly hellhound to ever exist. Quintus (Daedalus) was her original owner, but, after asking Nico Di Angelo to kill him, Percy becomes the hellhound's owner. While Percy is in the "mortal world", Charles Beckendorf takes care of her at Camp Half-Blood. Rescues Percy while in the Labryrinth.
• Hippalectryons - The Hippalektryons are an endangered animal that is part chicken, part horse. In "Battle of the Labyrinth," they are seen at the Triple G Ranch.
• Hippocampus - Hippocampi are from waist up stallion horses and from waist down have a fish tail. One is said to take a liking to Tyson, and soon enough he named it Rainbow. They are also called "fish ponies" by Tyson.
  • Rainbow: A Hippocamus who befriends Tyson in "The Sea of Monsters. Loves to give Tyson rides all over the sea."
• Hyperboreans: Ice giants who freeze into ice when defeated. They side with Kronos in The Last Olympian.
• Hydra: A monster with nine heads. Every time a head is chopped off, two new heads grow back. This monster appears in The Sea of Monsters where its life force is linked to the Monster Doughnut Shop as another one pops up every time the Hydra regrows a head. In The Lightning Thief film, the creature takes the form of five janitors in the Parthenon replica in Tennessee and refers himself as "We" and is ultimately defeated by the use of Medusa's head.
• Kampê: A snake-haired, centauroid creature that is half-woman, half dragon with wings and the heads of various mutated wild animals growing from her human torso. She is a monster that imprisoned the Hundred-Handed Ones and Cyclopes during the First Great War. She is feared by all, and is defeated by Briares in the "Battle of the Labyrinth" by being crushed by boulders.
• Keres: A bunch of battlefield spirits of famine and disease that feed on violent deaths. They reside in the Underworld and support the Titans but do not assist them in "The Last Olympian." In "The Demigod Files," a bunch of them attacked Percy, Thalia, and Nico where one of them poisoned Percy. Lucky for him, Bob the Titan managed to heal him.
• Laistrygonians: Large, muscular cannibals who serve as the brawn of Kronos's army. Known Laistrygonians in the series are Joe Bob, Marrow Sucker, and Skull Eater
• Ladon: The giant dragon who is one of the offspring of Echidna. It defends the Hesperides' apple tree. Ladon poisons Zoë Nightshade in The Titan's Curse.
• Lotus-Eaters: A bunch of them run the Lotus Hotel and Casino in The Lightning Thief.
• Manticore: These monsters have human faces and the bodies of lions as well as thorny tails. Dr. Thorn is a manticore.
  • Dr. Thorn: He is a manticore in the form of the vice principal of Westover Hall, the school that Bianca and Nico di Angelo attended. He has two eyes of different colors, one blue and one brown. His nostrils flare up when he talks.
• Medusa: The gorgon monster who under the moniker of "Aunty Em" attempted to lull Percy, Annabeth, and Grover into a false sense of security and turn them into stone statues. She is defeated, and her severed head is mailed to the gods of Olympus as proof of the trio's courage (though Grover notes that it is more akin to impertinence). Percy's mom uses her head to turn Gabe Ugliano to stone.
• Minotaur: The Minotaur is part-man, part bull. The monster of the labyrinth that chased Percy all the way to Camp Half-Blood. He defeats the monster atop Half-Blood hill and claims its broken horn as a spoil of war. The Minotaur returns in The Last Olympian as a general for Kronos's army at Williamsburg Bridge and now wearing armor. It was defeated by Percy again. In the film adaption, the Minotaur's head resembles a Cape Buffalo's head.
• Myrmekes: A race of giant ant-like creatures that like shiny things like gold. In "The Demigod Files," A bunch of Myrmekes trapped Charles Beckendorf in their nest.
• Nemean Lion: A lion that is one of the children of Echidna and Typhon. Luke and Atlas sent the Nemean Lion to the National Air and Space museum to stop the group of questing Hunters and Demigods. It battled with Percy Jackson, but was hard to defeat because of its bulletproof and sword-proof pelt. Percy eventually defeated it by throwing astronaut food into its mouth to expose its one unprotected surface, its mouth.
• Ophiotaurus: A half-cow/half-snake monster. It is an ancient monster that could bring down the gods if it was slain and its entrails were sacrificed. It was nicknamed Bessie by Percy Jackson who initially assumed it was female, although Grover later informed him that it was a male. Percy saved it from a trawler's net after being fetched by the Hippocampi.
  • Bessie: Bessie is the Ophiotaurus that Percy meets in "The Titan's Curse." Percy named it because of its bovine appearance, but it was in fact a male. Bessie was supposedly the creature that Artemis was hunting because it could destroy Olympus. She also briefly appeared in "The Last Olympian" where Percy sees him an aquarium.
• Orthrus: A two-headed dog owned by Geryon.
• Pegasus: Pegasi are winged horses.
  • Blackjack: He is the pure black version of Pegasus and Percy's loyal friend. He is first introduced in the second book The Sea of Monsters on the Princess Andromeda, Luke's demon cruise ship, where Percy rescued him from Kronos's minions. Ever since then, Blackjack has felt like he has to pay Percy back for saving him and he does whatever Percy asks.
• Peleus: A dragon that guards the tree that Thalia was previously within.
• Pit Scorpion: A deadly type of scorpion that appears in "The Lightning Thief." When Luke brings Percy into the woods and reveals his allegiance to Kronos, he summoned a Pit Scorpion to attack Percy. He tells Percy he should not go for his sword, as the pit scorpion can kill in 60 seconds, and can jump up to fifteen feet. When Luke disappears, Percy manages to kill it even though it managed to sting him. With the help of the wood nymphs, Percy recovered from its poison.
• Satyr: Half man, half goat. Grover Underwood is also a satyr.
  • Coach Gleeson Hedge: He is a satyr. Grover made a reference to him in "The Last Olympian" where he tried to summon Pan's spirit to help fend off some badgers. He played a part in the "Heroes of Olympus" series.
  • Ferdinand: Ferdinand is Grover's uncle who was one of the victims of Medusa in the Garden Gnome Emporium. When Kronos' army was hiding out there in "The Last Olympian," his statue form is now missing an arm and has graffiti on it without Medusa watching over it.
  • Leneus: Leneus is a satyr who is a member of the Council of Cloven Elders. He is killed in The Last Olympian and is reincarnated as a laurel. He hates Grover and thinks he is a liar. When he dies, Grover takes his spot in the Council of Cloven Elders.
  • Maron: Maron is a satyr who is member of the Council of Cloven Elders. He only appears in book four, when he, Silenus and Leneus try to exile Grover because they think that Pan, the god of the wild, is still alive and Grover is a just lying about his death. He and the other members of the Council are described as being old and fat satyrs.
• Scylla: One of the two monsters (the other being Charybdis) that live on either side of a narrow channel of water in The Sea of Monsters. Should a ship sail too close to her, she uses her six heads to pluck off crew members upon deck and devour them. According to Clarisse (daughter of Ares), if the crew hid below deck, Scylla would just pick up the whole boat and crush it.
• Scythian Dracaenae: A race of humanoid femals with twin snake tails in place of legs. They make up a considerable portion of the Titan Lord's forces.
  • Queen Sess: The Queen of the Scythian Dracaenae who appears in "The Last Olympian." She fought Chiron alongside Kronos and was killed when Chiron fired one of his arrows in between Queen Sess' eyes.
• Sea Serpent: One was seen amongst the sea monsters in Oceanus' army. Deimos is seen riding one in "The Stolen Chariot."
• Sirens: Dangerous bird-women whose sweet songs have led many sailors to watery deaths. Their hymn is almost Annabeth's undoing.
• Skeleton: Skeletons were used by various people like Hades. In "The Lightning Thief," Hades had skeletons in army uniforms guarding his palace. In "The Battle of the Labyrinth," Nico manages to employ them as part of a ritual that will enable him to call the spirit of his sister to speak with her. In "The Last Olympian," Nico and Hades manages to bring a bunch of Skeletons to help fight the Titans. They are later seen constructing a cabin at Camp Half-Blood that is dedicated to Hades.
  • Skeleton Warriors: A bunch of skeletons armed with weapons. In "The Titan's Curse," some skeleton warriors ambushed Percy, Thalia, Zoe, Grover, and Bianca in New Mexico. Due to her being a child of Hades, Bianca managed to destroy them.
• Sphinx: A Sphinx is a monster with the head of a woman and the body of a lion. Percy Jackson and his friends encountered the Sphinx while navigating the labyrinth. Rather than tell riddles, the Sphinx asked historical questions.
• Stymphalian Birds: A flock of birds once attacked Camp Half-Blood in The Sea of Monsters. Percy and Annabeth used Chiron's music so Apollo's cabin could shoot them down.
• Sybaris: In "The Titan's Curse," Atlas used her teeth to create Skeletons.
• Talos: Talos is a giant automaton. Percy, Thalia, and Bianca fight a prototype of Talos in the Junkyard of the Gods. Apparently, he has a manhole at the base of his foot for 'servicing'. Bianca went in to mess up his circuit so they could beat him. He fell on some power lines thus electrocuting Bianca.
• Telekhines: Dog-faced sea demons that reforged Kronos's blade in the fourth book. Some set Percy on fire in the fourth book. They also appear in the fifth book. In the fourth book, they are referred to as "telekhines", however in the fifth book, they are referred to as "telkhines", without the second "e". This may be a typographical error or something different of the author's choice.
• Typhon: A very powerful monster. He sired many monsters by Echidna. He lives and sleeps inside Mount Saint Helens. Percy is such a powerful demigod that he almost wakes Typhon during his visit there. In The Last Olympian, he awakes and moves across America and destroys everything in his path. The gods of Olympus try to stop him but he is too powerful. In the end, Poseidon and his army help defeat him.
• Wood Nymph: Wood Nymphs are a type of Nymphs that are associated with specific lands.
  • Juniper: Juniper is a tree nymph. She is Grover Underwood's girlfriend, and in "The Battle of the Labyrinth", she informs Percy that she has seen Luke Castellan using the entrance to the Labyrinth and that she has also seen Quintus/Daedalus using the entrance to the Labyrinth.

Mortals

• Darrin: One of the many people in the Lotus Casino. He is described as about thirteen, and "some Elvis impersonator's son". Percy meets him at a Virtual reality shooter game. He has apparently been in the Lotus Casino since 1977.
• Gabriel "Gabe" Ugliano: Known as "Smelly Gabe," he was Percy's stepfather. In appearance, he is heavy and bald, wearing thrift store clothes often. He managed the Electronics Mega-Mart in Queens as an occupation. As Percy described him in The Lightning Thief, he "was nice the first thirty seconds we knew him, then showed his true colors as a world-class jerk." During summer break from school, Gabe asks him for money for beer and for his poker games with his friends. Supposedly he can easily guess how much money a person has. It is implied that, at least once, he hit Percy's mother. Grover later tells Percy that Sally (Percy's mother) married Gabe to protect Percy from monsters who would have tracked him down otherwise. He smelled so "repulsively human" that his smell hid Percy's demigod scent from monsters. If she had not married him, monsters would have found Percy sooner. At the end of Book 1, he is turned to stone by Percy's mother (using Medusa's severed head) and sold as a statue, "The Poker Player", earning lots of money in the process.
• May Castellan: Luke's mother who attempted to become the Oracle. Since Hades's curse prevented her from taking it, she was driven crazy and instead received small glimpses of her son's terrible future. She made huge amounts of sandwiches, burnt cookies, and Kool-Aid for Luke, believing that someday he would return home. She also gave him a blessing to receive the curse of Achilles. It was shown that she had numerous clippings of Hermes from advertisements and many beanbag monsters sitting in the house and on the front lawn.
• Dr. Frederick Chase: Annabeth's father. He first appears in The Titan's Curse. He allows Percy, Thalia and Zoë to borrow his car to drive to Mount Tamalpais (Mount Othrys). Annabeth's father is a professor of military history. During The Titan's Curse, he was studying the Third Battle of Ypres. He owns a Sopwith Camel. He and his daughter had a lot of disagreements in the past, which is why she ran away home when she was seven years old. He lives in San Francisco with his wife and two sons, Bobby and Matthew. In The Titan's Curse, he battles the monsters on the Princess Andromeda with bullets melded with celestial bronze.
• Mrs. Dare: Rachel's mother. She briefly appears in The Last Olympian. She went to Clarion Ladies' Academy, a finishing school for society girls in New Hampshire, and wants Rachel to go there as well.
• Paul "Blowfish" Blofis: Sally Jackson's boyfriend and later husband, and thus Percy's stepfather. Percy and his mother reveal to Paul the truth, and at first he only half believes them. When Percy, Nico, and Mrs. O'Leary come unexpectedly into Sally's apartment, Paul fully believes, and thinks it's "awesome!". Paul turns out to be an excellent swordsman due to the fact that he was a Shakespearian actor in college and assists in the fight to save Olympus in The Last Olympian. He asks Percy for permission before proposing to Percy's mother.
• Preacher: A preacher who raised money supposedly for orphans and spent it instead on his mansion until he was caught by the police. He died in a police chase when he drove his "Lamborghini for the Lord" off a cliff. He was sent to the Fields of Punishment in the Greek Underworld, but believed that he was in the Christian hell.
• Rachel Elizabeth Dare: A clear-sighted mortal girl who is able to see through the Mist. She is first encountered by Percy during The Titan's Curse as he flees from the skeletons summoned by Atlas. After mistaking her for a monster and realizing she is human, Percy discovers that she can see through the mist. She leads the skeletons away from Percy. Rachel goes to the same school as Percy in "The Battle of the Labyrinth," realizing that the cheerleaders are actually empousai. In The Battle of the Labyrinth, she aids Annabeth and Percy by guiding them through the labyrinth to Daedalus's workshop. From there she, Percy, Annabeth, and Nico escape, only to enter again to locate Grover and Tyson. She is present at the deathbed of Lord Pan and, like the others, takes part of his essence within her. By throwing her hairbrush at Kronos, she provided enough of a distraction for Percy to escape the Titan Lord's time manipulation. It is hinted throughout the series that she harbors romantic feelings for Percy. In The Last Olympian, she begins having strange visions and becomes the new Oracle of Delphi after Hades's curse is lifted, under the guidance of Chiron and Apollo. Her first act as the Oracle is to deliver the Great Prophecy of the next generation of heroes.
• Sally Jackson: The daughter of Jim and Laura Jackson. She is the mother of Percy and she was married to "Smelly" Gabe." She then turned him to stone with the head of Medusa, and married Paul Blofis in the fifth book. In the beginning of the series, it is indicated that Sally works at a candy shop called "Sweet on America" and said that she wanted to be an author when she was young. In the third book, Percy guesses that Sally can see through the Mist and he believes that this was probably the reason Poseidon took interest in her. In the first book, she was thought to be killed by the Minotaur. Later on, it was discovered that she survived and that she was still alive.
• William Dare: He is Rachel Elizabeth Dare's father and first appears is in The Last Olympian. He owns a land developing company and is very wealthy. His family lives in a mansion in Brooklyn, where Rachel lives on the top floor. Rachel hates her father because of his job, but he seems to care about her. He said that he and her mother had really been looking forward to the vacation, but, according to Rachel, they both hate the beach, and are just too stubborn to admit it. He supported Rachel's going to finishing school. He walked into Rachel's room in Percy's dream, wearing pajamas with "WD" monogrammed on the pocket.

Names

Percy is one of the few demigods whose last name does not reflect his godly parent, though his first name does. Many of the campers at Camp Half-Blood have last names that consist of a traditional role or trait of their parent. Other last names are often commonplace: Rodriguez, Nakamura.

• Percy Jackson: "Percy" is a nickname for Perseus, Percy's real name, who was a son of Zeus. Percy's godly parent is Poseidon.
• Annabeth Chase: "Annabeth" is an anagram of Athena with a couple of extra letters. Also, "Chase" is a near homonym to "Chaste". Daughter of Athena.
• Clarisse La Rue: "Clarisse" is an anagram of Ares with extra letters. Also, to rue is to regret something.
• Grover Underwood: Without the suffix "r" Grover's name is "Grove" referring to The Wild. Also, Underwood contains the word "wood" referring to trees. He is a Satyr, worshipper of Pan, the god of The Wild.
• Bianca and Nico di Angelo: "d'Angelo" means "of the angels", referring to death. Children of Hades.
• Connor and Travis Stoll: Homonym to "stole". Hermes is the god of thieves. Children of Hermes. Percy himself pointed this out but neither of the Stoll brothers understood the joke.
• Jake Mason: A mason works with stone. Son of Hephaestus.
• Katie Gardner: alternate spelling of "gardener". Daughter of Demeter.
• Pollux and Castor (Last name never revealed): Pollux is the name of a demigod son of Zeus. Castor was the name of this demigod's twin brother (but, he was the son of their mortal father). In the Myth, Castor died, foreshadowing his death in the book. Twins of Dionysus.
• Charles Beckendorf: Char is another word for burn. Son of Hephaestus, god of fire.
• Lee Fletcher: to "fletch" is to add feathers to an arrow. Son of Apollo. And it may, also, be a reference to Lee Adama, a character from the TV series Battlestar Galactica, who was known by Captain Apollo.
• Michael Yew: yew is a type of wood used to make longbows. Also a son of Apollo.
• Silena Beauregard: literally, "beauregard" means "good to look at" in French, the language of love. Daughter of Aphrodite.
• Will Solace: The prefix "Sol" is the Roman name for Helios, also "sol" often refers to the Sun, and Apollo drives the sun chariot. Solace also means comfort or consolation during a time of sadness. Since Apollo is the god of medicine, and since people are distressed when in pain, this is an appropriate name. Son of Apollo.
• Thalia Grace: In mythology Thalia is the name of one of the Charites, also called the Graces. Daughter of Zeus.
• Leo Valdez: "Leo" could refer to Leonardo da Vinci, an inventor and artist, among other things. Son of Hephaestus, god of technology, craftsmen, artisans, etc.
• Piper McLean: In The Lost Hero, Piper reveals that her Grandpa Tom named her Piper because she had a beautiful voice even as a baby. The name Piper means "pipe player". The beautiful voice might be a reference to the fact that she has the Charmspeaking ability, the ability to persuade someone to do things, a power few children of Aphrodite have. Daughter of Aphrodite, goddess of love and beauty.
• Jason Grace: To appease Hera, Zeus named Jason after Hera's favorite hero, Jason, the leader of the Argonauts. Son of Jupiter(Zeus), Champion of Juno(Hera).