List of SpongeBob SquarePants characters
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The characters in SpongeBob SquarePants were created by artist, animator and former marine biologist Stephen Hillenburg. In addition to the series' main cast, various celebrities have voiced roles in SpongeBob SquarePants. Notably, Ernest Borgnine and Tim Conway voice the roles of recurring characters Mermaid Man and Barnacle Boy respectively, while others have taken a cameo part.
Creation and conception 
Stephen Hillenburg conceived the characters for SpongeBob SquarePants in 1984, while he was teaching and studying marine biology at what is now the Orange County Ocean Institute. During this period, Hillenburg became fascinated with animation, and wrote a comic book entitled The Intertidal Zone starring various anthropomorphic forms of sea life, many of which would evolve into SpongeBob SquarePants characters, including "Bob the Sponge", who was the co-host of the comic and resembled an actual sea sponge as opposed to SpongeBob. In 1987, Hillenburg left the institute to pursue his dream of becoming an animator.
Main characters 
- SpongeBob SquarePants (Tom Kenny) is the series' title character and protagonist. He is a yellow sea sponge who physically resembles an artificial, rectangular, kitchen-type cleaning sponge; he wears brown short-pants, a white shirt and a red tie. He lives in a pineapple house and is employed as a fry cook at a fast-food restaurant called the The Krusty Krab, where many stories take place; he takes pride in his work and seems to worship or venerate the Krabby Patty. SpongeBob's hobbies include practicing karate with Sandy, as well as jellyfishing and blowing bubbles with Patrick. He attends Mrs. Puff's Boating School but has never passed; his lack of a driver's license is a running gag throughout the series. It is implied that, although he has no experience, he has talent in the arts. Green and purple were early color choices for the character before yellow was chosen. He is weak and fragile, shown in MuscleBob BuffPants when he can't lift a glass of tea, and he claims to be "pumping iron" with his plush toys. His first appearance was in "Help Wanted". Gary the snail is SpongeBob's only pet.
- Patrick Star (Bill Faggerbakke in 1999-present) is a pink starfish who lives under a rock and whose most prominent character trait is his low intelligence. He is friends with Spongebob and often encourages activities that get the two into trouble. While typically unemployed throughout the course of the series, Patrick holds various short-term jobs as the storyline of each episode requires. He is good-natured, kind, and is "the tough one" of the two who is often called to fight SpongeBob's battles for him (although he usually gets distracted). Patrick is shown to have a mean temper in some episodes. Despite being portrayed as a largely unintelligent character, it is mentioned in "The Bully" that he went to community college. In the episode "Patrick SmartPants", he refers to Spongebob and Sandy as "Robert" and "Sandra". His first appearance was in "Help Wanted". He is a very childish person shown of his drooling, his laziness and immaturity.
- Squidward Q. Tentacles (Rodger Bumpass) is an octopus cyanea with a large nose; he is SpongeBob and Patrick's ill-tempered, grouchy next-door neighbor with a snobby attitude and a sarcastic sense of humour. He plays the clarinet and loves to paint self-portraits in different artistic styles, which he hangs up around the walls of his house shaped like an Easter Island head-sculpture. He abhors SpongeBob and Patrick, as well as his current occupation at the Krusty Krab. He regularly falls asleep on the job and acts condescending toward customers. In the episode "Squidville" it is shown there are other "Squids" in his species who live in Easter Island heads, are very cranky and play clarinets.
- Mr. Krabs (Clancy Brown) is a red crab who owns and operates the Krusty Krab restaurant where Spongebob works. He is self-content and intelligent. He is obsessed with money. He has a grandfather named Redbeard and lives in an anchor with his daughter Pearl, who is a whale. The Krusty Krab was originally a retirement home called "The Rusty Krab" which he bought after returning from fighting in the war; when it went bankrupt, he turned it into a restaurant and renamed it "The Krusty Krab". In some episodes, it is shown that he and Mrs. Puff have a mutual crush on each other. It is revealed in the episode "Sleepy Time" that he was born November 30, 1942. He started the Krusty Krab in 1980. He takes pride in money, his invention the Krabby Patty, and his superiority over his rival Plankton and ""his"" restaurant, The Chum Bucket.
- Sandra "Sandy" Cheeks (Carolyn Lawrence) is a squirrel from Texas. She has a number of athletic interests, such as "sand-boarding" and karate, and is a rodeo champion. She is also a scientist, explorer and inventor. Being from the surface, she lives in a tree which is inside a glass dome so she can breathe, and also wears a space-suit and helmet to travel outside of her tree-dome. Whenever any aquatic creatures enter her air-filled dome, they must wear helmets filled with water so that they can breathe. It was mentioned in Atlantis SquarePantis that her full forename is Sandra.
- Sheldon J. Plankton (Doug Lawrence) is a plankton. He is the owner of Chum Bucket, the rival restaurant to the Krusty Krab, and archenemy to Mr. Krabs. He constantly tries to steal the Krabby Patty Secret Formula, but is always unsuccessful (except, temporarily, in The Spongebob Squarepants Movie). He wishes to rule the world. His wife, Karen, is a computer he created.. He is considered the main antagonist of the series and in the episode "Plankton's Pet" he gets a pet amoeba called Spot.
- Garold Wilson "Gary" Snail Jr. (Tom Kenny) is SpongeBob's pet Sea snail. Within the series, snails are analogous to cats, so Gary almost always vocalizes like a feline. Despite this, other characters can understand and communicate with him. Depicted as a level-headed character, Gary sometimes serves as a voice of reason for SpongeBob, and solves problems that his owner cannot. He is sometimes nicknamed "Gare-Bear" by SpongeBob, and it is revealed in "A Pal for Gary" that his full first name is Garold.
Recurring characters 
- Mrs. Puff (Mary Jo Catlett) - A pufferfish with blonde hair, who is the owner and teacher of a boating school (analogous to driving school, as the "boats" are underwater equivalents to cars). Her first appearance with in the episode "Boating School", which first aired on August 7, 1999. She dreads instructing SpongeBob due to his inability to drive without crashing. In the episode "Krusty Love", it is revealed that her husband is dead and was turned into a lamp. Also shown in the episode "Krusty Love", Mrs. Puff once dated Mr. Krabs. It is revealed in the episode "No Free Rides" that Mrs. Puff is not her real name. In the episode "Demolition Doofus", it is revealed that Mrs. Puff is allergic to flowers and as a running gag it is shown she gets in trouble with the police.
- Pearl Krabs (Lori Alan) is Mr. Krabs' 16-year-old (as of the episode "Whale of a Birthday") sperm whale daughter. The series has yet to explain their disparity in species, although in the book SpongeBob's Trivia Book, Mr. Krabs explains that Pearl takes after her mother, meaning her mother was apparently also a whale. Occasionally in the series, Mr. Krabs will exclaim, " Mother of Pearl!" referencing her mother. Her mother is never seen nor addressed in the series (Krabs is portrayed in the series as being a single man). Pearl is frequently embarrassed by her father's cheap attitude, and often forces him to try and change his habits.
- Karen (Jill Talley) is Plankton's nagging computer "WIFE" (as in an acronym for "Wired Integrated Female Electroencephalograph"). She apparently has a mind of her own, to the point of making fun of Plankton. Karen usually helps Plankton in his schemes to steal the Krabby Patty secret formula although on occasions Plankton rejects her ideas and then takes them as if they were his own. It is revealed in The SpongeBob SquarePants Movie that she never agreed to marry Plankton. Karen also made a cameo in an episode of The Fairly OddParents called "Love Triangle". She is the monitor at the hospital after Poof catches a disease.
- Mermaid Man (Old: Ernest Borgnine (1999-2012) and Joe Whyte (2012–present), Young: Adam West) and Barnacle Boy (Old: Tim Conway, Young: Burt Ward) are two elderly and partially senile superheroes who live in a retirement home, whom SpongeBob and Patrick watch on television. Mermaid Man is the older of the two and is the leader, while Barnacle Boy is his sidekick. Mermaid Man might be a reference to Poseidon, having what looks like Poseidon's trident. It is most likely that they are parodies of Aquaman and Aqualad, although the fact that their young versions are voiced by Adam West and Burt Ward, as well as the iconic use of onomatopoeic words, hints that they parody Batman and Robin. Mermaid Man is known for completely forgetting things, yelling "EVILLLLL!" whenever he hears the word, and Barnacle Boy seems to be the smarter of the two. It is implied in an episode that they are brothers. The male counterpart to a mermaid is a merman; Borgnine was briefly married to Ethel Merman. It was revealed in the episode entitled "Mermaidman Begins" of the 8th season, that Mermaid Man's name was Ernie. It is unknown if it is just his nickname or his real first name. Also in this episode says that Barnacle Boy's real name is Tim. But another episode said his real name was Kyle. Borgnine and Conway had previously appeared together on the 1960s TV series McHale's Navy. Borgnine died on July 8, 2012 and since late 2012, Mermaid Man has been voiced by Joe Whyte, who voiced Mr. Krabs in some video games.
- Larry the Lobster (Mr. Lawrence) is a lobster lifeguard of the Goo Lagoon. Larry is a bodybuilder and workout fanatic. He was considered a lifeguard on "SpongeGuard on Duty", but in other episodes, he is not and simply just hangs out at the beach. Despite his large and muscular physique, he is sometimes shown to be somewhat of a coward. He once overdosed on tanning pills. He also drives an SUV in one episode.
- Scooter (Carlos Alazraqui/Clancy Brown) - A parrotfish who enjoys surfing. He allegedly died and became an angel in the second-season episode "Bubble Buddy", except he also returned in future episodes. Scooter talks like a stereotypical surfer dude, but after Season 3 he had different voices in each episode he appeared in. He is mainly seen at Goo Lagoon.
- Nat (Billy West) - A male yellow fish that is a common background character on the show. His last name is revealed in "Missing Identity" and his first name was revealed in "Plankton's Regular". He first appeared on the fifth episode of SpongeBob SquarePants, "Ripped Pants", as a cameo. He appears in many episodes, especially the newer ones. His biggest role is in "Plankton's Regular".
- The Flying Dutchman (Brian Doyle-Murray) is an irascible pirate ghost named after a ghost ship, The Flying Dutchman. He lives underwater in a giant ship, and collects souls. He has supernatural powers, such was intangibility, levitation, teleportation, energy projection, shapeshifting, interdimensional travel, matter transmutation, and wish granting. He is known for having numerous awards in tying loops but however does not know how to tie shoelaces as revealed in "Your Shoe's Untied" and hangs a sock on his ghostly tail. It is revealed in "Shanghaied" that he cannot eat without his sock.
- Sadie Rechid (Carolyn Lawrence) An orange fish who is married to Fred. She has four children and two sisters named Nazz and Patty.
- Patchy the Pirate (Tom Kenny) is a live-action character who is a pirate and the president of the SpongeBob fan club. He lives in the city of Encino, California. He is normally present in specials (one-off double length episodes), often in a dual narrative with the animated Spongebob, although sometimes he merely introduces the episode. He made a special guest star appearance on Big Time Rush in the episode "Big Time Beach Party" with Carlos Pena, Jr. and Logan Henderson. Patchy has a next-door neighbor named Mrs. Johnson who offers him cookies and has an electric rocket propelled wheelchair. Patchy works at a fast-food restaurant called The Poop Deck. His boss' name is Mr. Pirateson.
- Potty the Parrot (Stephen Hillenburg and Paul Tibbitt) is the Patchy the Pirate's "annoying" pet parrot. Potty is a crudely made puppet with very obvious strings. He is very obnoxious, and normally annoys and talks back to Patchy.
- Elaine (Mr. Lawrence) is a live-action announcer and news anchorfish, resembling a cut-out of a bass fish. Elaine appears in numerous episodes, including the beginning intro of the show. His name is revealed to be Elaine in "The Great Patty Caper", though he is known as Johnny in Battle for Bikini Bottom. In the chapter books Elaine looked more like Perch Perkins.
- Harold SquarePants (Tom Kenny) and Margret Bubblebottom SquarePants (Sirena Irwin) are SpongeBob's parents, who more resemble sea sponges rather than SpongeBob's shape as a kitchen sponge.
- Squilliam Fancyson (Dee Bradley Baker) is Squidward Tentacles's wealthy arch-rival who has been able to succeed in everything Squidward has only dreamed of doing. He and Squidward compete in the series on many occasions and Squidward normally does not win their competition(s), although there are some episodes where Squidward is triumphant. Though sometimes mistaken as a relative of Squidward due to their similarities, they were band classmates in high school and are not related.
- Mrs. Krabs (Paul Tibbitt/Sirena Irwin) is Eugene's overbearing mother first appearing in "Sailor Mouth". Plankton has a small crush on her in "Enemy in Law". but it is later revealed he is only dating her for the Krabby Patty formula. She is also shown to be quite poor while raising her son through his childhood, as shown the episode "Friend or Foe?".
- Man Ray (John Rhys-Davies & Guy Siner/Bob Joles) and the Dirty Bubble (Charles Nelson Reilly/Tom Kenny) are villains against Mermaid Man and Barnacle Boy. Man Ray (not the famous photographer of the same name) has a man's body with a ray shaped mask and helmet, while the Dirty Bubble is portrayed as a literal giant bubble with a face. Man Ray is based on Black Manta, Aquaman's archenemy. Charles Nelson Reilly originally voiced the Dirty Bubble, but Tom Kenny has portrayed the character since Reilly's death in 2007.
- Perch Perkins (Dee Bradley Baker) is a news reporter. He first appeared in "The SpongeBob SquarePants Movie" as an announcer for the Krusty Krab 2. He appears as a minor character in the series afterwards having his purple color from the movie changed to orange.
- Dr. Forrest (Rodger Bumpass) is Bikini Bottom's doctor, often seen in the hospital. His name is revealed in "Slide Whistle Stooges" and "Shuffleboarding". He is mostly purple, and has occasional appearances throughout the series, but in the episode "Once Bitten", there is a similar looking doctor that looks like Dr. Forrest, except he is orange and goes by the name Dr. Gill Gilliam though they could be brothers or close relatives.
- Officers Nancy and John (Grey DeLisle & Dee Bradley Baker) – Officer Nancy (a purple female cop fish with blonde hair) and her partner John (an orange fish) are the two most commonly seen cops in Bikini Bottom, most prominently in Season 3. The two officers, especially Officer Nancy, are seen less in recent episodes, but their latest appearance was in "Mr. Krabs Takes a Vacation" where thanks to Mr. Krabs two bank robbers crash through the roof of their police car and land in their backseat without them having to do anything.
- Nancy Suzy Fish (Sirena Irwin/Grey DeLisle) is an often seen, but infrequently heard, yellow dress-wearing, white-haired fish with gray skin. Her name was revealed in "MermaidMan and BarnacleBoy V".
- Old Man Jenkins (Doug Lawrence, Tom Kenny, and Dee Bradley Baker) - An elderly fish who used to live in the Rusty Krab rest home before it became the Krusty Krab restaurant, and currently resides at Shady Shoals Retirement Home along with Mermaid Man and Barnacle Boy. His appearance changes in almost every episode he appears. His most memorable appearance is in "The Sponge Who Could Fly" as the antagonist when he becomes Sailor Jenkins and Cannonball Jenkins after giving up farming. He is friends with Mama Krabs as seen in "Sailor Mouth" and his first major appearance, "Friend or Foe?".
- Fred (Doug Lawrence/Jim Cummings), better known as the guy who shouts "MY LEG!", is a brown fish who was the first of the regular generic character models to appear in the series. He first appears in "Reef Blower" but the famous quote does not come until "Boating School". Fred is most often seen at the Krusty Krab, such as in "Arrgh!", when he screams "MY LEG!" after Mr. Krabs throws him out of the Krusty Krab, and in "Jellyfish Hunter", when he sings about a jelly sandwich he eats. Fred's name is revealed in "Patty Hype". One of Fred's famous lines is "Rev-up those friers, 'cause I am sure hungry for one-" He is then interrupted by Mr. Krabs who says "Can't you see we're closed?!" In which Fred responds with the famous "MY LEG" line.
- Tom (Doug Lawrence/Dee Bradley Baker/Carlos Alazraqui) – Tom is a green fish who wears a purple shirt. He is always seen walking around Bikini Bottom. His most famous and memorable appearance is in "Chocolate with Nuts" when he chases SpongeBob and Patrick all over town screaming crazily, "CHOCOLAAAATTTE!". Finally he catches up with them, but it turns out that he just wanted to buy all of their chocolate. Episodes such as "Pizza Delivery" and "Fools in April" show that he has a habit to obsess over his drinks, often to a violent extent.
- Mary (Sirena Irwin) – Mary (or "Lazy Mary" as she's called by her mother) is an eldery fish who lives in Bikini Bottom with her even more elderly, grumpy mother. She is very annoyed about having to take care of her mother who is very mean to her. Her most memorable appearance was in "Chocolate with Nuts" when Spongebob and Patrick tricked her mom into buying some so she could rub it on her skin and make her "live forever."
- Charlie (Dee Bradley Baker) is an aquamarine fish often as a background character in the show. His name was revealed in while he was in a TV commercial with Mr. Magic endorsing a product called "Mr. Magic's Magical Magic Kit".
- Billy (Kevin Michael Richardson) is an olive green fish seen about everywhere in Bikini Bottom. His name was revealed in Professor Squidward when Squidward tells how he likes it putting his name on the board. His latest appearance was in the episode Demolition Doofus when Mrs. Puff was standing right next to him. He talks in many voices. His first appearance was in Life of Crime. It's hinted that he's part werewolf in The Great Patty Caper.
- Harold "Bill" Reginald (Jeff Bennett) is a blue reef shark with spiky teeth and a red speedo. His name was revealed in both Have You Seen This Snail? and in the Fiery-Fist o' Pain when Tina Fran was saying his name. His first appearance was in Ripped Pants.
Minor characters 
- Painty the Pirate (Patrick Pinney) – A painting of a pirate head that sings the SpongeBob SquarePants theme. Painty also makes minor appearances in several episodes. He has had an appearance in almost all of the episodes.
- Bubble Bass (Dee Bradley Baker) – An obese Bass who is SpongeBob's rival since he is picky about food. He made his first appearance in "Pickles," and also appears in "F.U.N." when SpongeBob and Plankton are at the movie theatre. He made a third appearance in "Plankton's Good Eye" where he is saved from his burning house by Plankton.
- Bubble Buddy (Brad Abrell) – A bubble friend that SpongeBob makes himself after Patrick, Sandy and Squidward were too busy to play with him. He causes a lot of trouble in Bikini Bottom such as fussing over his order at the Krusty Krab, paying Mr. Krabs with bubble money and hogging the porta potty at Goo Lagoon. He leaves Bikini Bottom at the end of the episode but returns when he wants SpongeBob to babysit his son, Shiny who causes even more trouble than his father.
- Stanley S. SquarePants (Christopher Guest) – SpongeBob's cousin who has a similar appearance to SpongeBob, but is much taller. SpongeBob and Stanley try to help each other whenever possible. Stanley is accident-prone and causes destruction wherever he goes. When Eugene discovered his inabilities he sent him over to the Chum Bucket where he literally blew up the place. He is not seen after the episode.
- Flatts (Thomas F. Wilson) – A mean flounder who went to boating school with SpongeBob and wanted to beat him up in the episode "The Bully". Flatts also appears in "Sandy's Rocket" and "Texas".
- Grandma SquarePants (Marion Ross) and Grandpa SquarePants (Tom Kenny) – SpongeBob's grandparents. Grandpa SquarePants is mentioned in past tense and Grandma SquarePants lives alone and sometimes treats SpongeBob like he is still a little sponge. Grandma SquarePants made her first appearance in the episode "Grandma's Kisses". She did not make her next appearance until the 2007 episode "Blackjack". She made two more appearances in the episodes "The Abrasive Side" and "Pet Sitter Pat".
- Neptune XIV of the Pacific (Paul Tibbitt/John O'Hurley (series) and Jeffrey Tambor (movie)) – The king of the ocean, King Neptune is a massive magical green merman with red glowing hair, although he looks slightly different from one appearance to another. Neptune also appears as one of the movie's characters, although with a very different appearance, including a blindingly bald head; in the movie, he is also shown to have a daughter named Mindy. In "SpongeBob and the Clash of Triton", it is shown that he has a son named Triton and is married to Queen Amphitrite. His name is also used frequently as a substitute for "God" in colloquial phrases (e.g. "Sweet mother of Neptune!" and "What in Neptune's name is that?").
- Craig Mammalton (Dee Bradley Baker) - an extremely tanned seal who is popular around town for his complexion. He appears in the episode "Sun Bleached" in which he throws a huge party only for those as tan as he is. SpongeBob and Patrick try to tan themselves to get into the party and end up being sun bleached.
- Chip - A potato chip that's one of Spongebob's friends. Chip has appeared in one episode ("I Had an Accident"). In the episode, Chip is favored the most by Spongebob out of the three friends. Chip is shown to be very polite. He showed Patrick and Sandy to the door when they left. When Spongebob leaves his house he says," Chip, if I don't come back, take good care of Gary." Gary then shows up and eats Chip. He is never seen again.
- Used Napkin - A used napkin that is seen in the episode ("I Had an Accident"). Used Napkin is liked the least out of the three friends. The only thing said to him is Spongebob in a harsh voice," We can go without the name calling Used Napkin!" It seems that he is rude. Used Napkin added "Used" to his name after his appearance in "Bubble Buddy".
- Penny - A penny that is in only one episode "I Had an Accident". Penny is one of Spongebob's friends in the episode. Penny has a great singing voice, shown when Spongebob sings his "Indoors" song he says, "Take it away Penny!" Patrick then is amazed by her talent. That specific penny is only in that one episode.
- Jack Kahuna Laguna (JKL) (Johnny Depp) – A surfer who prefers to be called JKL, and helps SpongeBob, Patrick and Squidward get home by teaching them how to surf. He only appears in the special episode "SpongeBob vs. The Big One". His initials are most likely a parody of Matthew McConaughey's mantra of "Just Keep Livin'" from his role in Dazed and Confused.
- Jim the Former Frycook or Jim the Krab King(Patton Oswalt) – A rich fry cook who formerly worked at the Krusty Krab and later quit because Eugene did not give him a raise in his pay. He now works at the finest restaurants of Bikini Bottom and visits the Krusty Krab sometimes. He is much wealthier than Mr. Krabs. He appears in "The Original Fry Cook".
- Lord Royal Highness (David Bowie) – The emperor of the lost city Atlantis. L.R.H seems to have somewhat of an extraterrestrial appearance. He only appeared in the special SpongeBob's Atlantis SquarePantis.
- Lord Poltergeist (Chris Elliot) – A pirate ghost who is the former first mate of the Flying Dutchman. He took the Dutchman's treasure while going for a pizza and never returned. He now haunts a boat house in Bikini Bottom with 3 of his own mates. In "Ghoul Fools" the Dutchman returned to take back his stolen treasure and punish Poltergeist and his crew with eternal torment.
- Janet (Clea Lewis) and Marty (Thomas F. Wilson) – Patrick mistakes them for his parents. They appear in the episode "I'm With Stupid".
- Kelpy G (Rodger Bumpass) – Squidward's favorite smooth jazz clarinet player. He first appears in "The Thing" and makes another appearance in "Smoothe Jazz at Bikini Bottom" when SpongeBob and Squidward sneak backstage at one of his concerts. SpongeBob ends up playing ukelele with Kelpy on stage after he was so impressed with SpongeBob's talent. The character is a cephalopod version of saxophonist Kenny G.
- Nicolas Withers (Alton Brown) – The host of the House Fancy television show, in which Squidward and his rival Squilliam were competing against each other over whose house was better.
- Triton (Sebastian Bach) – King Neptune and Queen Amphitrite's son. He is also the brother of Mindy even though Mindy was not shown in the episode "Clash of Triton". Triton was always fascinated by the "mortal" world. When King Neptune destroyed Triton's cure for all "mortal" diseases, Triton confronts King Neptune, forcing King Neptune to lock him away in a cell that shrinks 7% of the way. Triton's first appearance was on the episode "Clash of Triton".
- Mindy (Scarlett Johansson) – King Neptune's and Queen Amphitrite's daughter (who has so far only appeared in The SpongeBob SquarePants Movie) who tends to be sweeter and kinder than her dad, and helped SpongeBob and Patrick with their journey in the movie. Unlike her father King Neptune, brother Triton and mother Queen Amphitrite, Mindy has never been seen using magical powers. Patrick seems to have a crush on Mindy, often calling her pretty and hot. Interestingly, she does not appear alongside her family in "Clash of Triton". This absence is unexplained.
- Queen Amphitrite (Victoria Beckham) – The wife of King Neptune, and the mother of Triton and Mindy. She tends to be very caring of her husband, even though it is not proven she shows a minor dislike for Mr. Krabs, after he called her a prankster on the phone pretending to be Amphitrite.
- Blackjack SquarePants (John DiMaggio) – SpongeBob's older and meaner cousin who used to bully SpongeBob as a child in the episode "Blackjack". He was arrested for littering and then released. SpongeBob had thought Blackjack would be a huge brutish sponge who was planning to murder his parents, and set out to find them by visiting members of his family. When SpongeBob had reunited with Blackjack, it is shown that he had apparently not grown since he and SpongeBob last saw each other (when SpongeBob was a toddler), making him about as tall as SpongeBob's foot.
- Don the Whale - a weight lifting killer whale who hangs out with Larry the Lobster in the first few seasons. He has no dialogue in the series, but appears in the video game SpongeBob SquarePants: Lights, Camera, Pants! as a prison guard voiced by Dee Bradley Baker.
- Dennis (Alec Baldwin) – An assassin hired by Plankton to kill SpongeBob and Patrick.
- Grandma Tentacles -Not Much is Known about her, but she made a Minor appearance in Chum Friassee
- Mrs. Tentacles- She looks much like Grandma Tentacles, and makes a minor appearance in "Krusty Towers" where she helps Mr. Krabs make a batch of cookies for Squidward
- Karen 2 -Plankton's second computer wife after he got rid of Karen, later destroyed by the original Karen.
- Tyler - a toddler who was not allowed to Craig Mammalton's tanning party in "Sun Bleached," although his mother argued he was "the perfect shade of Tropical Toddler."
- Kevin Seacucumber -Leader of the Jelly Spoters in "I'm your Biggest Fanatic"
- Doodle-Bob - Drawing that Spongebob made in the episode "Frankendoodle". He antagonizes Spongebob until he is ultimately defeated with the use of the magic pencil he was created with.
Guest stars 
The characters of SpongeBob SquarePants have been well-received overall. The titular character SpongeBob has become very popular with both children and adults. The character's popularity has spread from Nickelodeon's original demographic of two to eleven-year-olds, to teenagers and adults, including college campuses and celebrities such as Sigourney Weaver and Bruce Willis. The popularity of SpongeBob translated well into sales figures. In 2002, SpongeBob SquarePants dolls sold at a rate of 75,000 per week, which was faster than Tickle Me Elmo dolls were selling at the time. SpongeBob has gained popularity in Japan, specifically with Japanese women. Nickelodeon's parent company Viacom purposefully targeted marketing at women in the country as a method of building the SpongeBob SquarePants brand. Sceptics initially doubted that SpongeBob could be popular in Japan as the character's design is very different from already popular designs for Hello Kitty and Pikachu. However, the characters have also attracted negative reception, including SpongeBob himself, who was listed as number four on AskMen's Top 10: Irritating '90s Cartoon Characters. SpongeBob SquarePants was ranked on TV Guide's top 50 cartoon characters.
Appearances in other media 
The characters of SpongeBob SquarePants have been parodied various times in popular culture. In 2007, the Amsterdam-based company Boom Chicago created a SpongeBob parody called "Back to Work!" in which a Chinese Patrick refuses to go to work and advocates freedom of speech and rights of leisure and income. During the same year, production company Camp Chaos created a SpongeBob parody entitled SpongeBong HempPants which features five of the series' characters parodied in the form of various drugs. The show was seen on VH1 and Comedy Central. The series has received mixed reviews from television critics; Adam Finley of TV Squad believed the series sounded "hilarious on paper", but ultimately did not demonstrate its full potential. SpongeBob and Patrick were also referenced in Phineas and Ferb when they dug a hole and found a sponge and a seastar. SpongeBob and Patrick also have an appearance in the Disney show Good Luck Charlie when Charlie's parents have a pink square and a yellow star puppet and are performing a potty training show on a fake television set. In the show Marvin Marvin, Bob thinks he sees SpongeBob in real life. SpongeBob has made some appearances in TV shows such as The Simpsons, Family Guy, Robot Chicken, Mad, Drawn Together, South Park, Futurama, and The Cleveland Show. In the Duck Dodgers episode "Finns of War" a parody of SpongeBob is shown as a busboy. In the movie REC 3: Genesis, a Spanish horror movie, there is a person who is dressed up as SpongeBob. His name is Sponge John.
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