Big Bad is a term originally used by the Buffy the Vampire Slayer television series to describe a major recurring adversary, usually the chief villain or antagonist in a particular broadcast season. It has since been used to describe annual villains in other television series, and has also been used in scholarly work discussing Buffy the Vampire Slayer.
On Buffy the Vampire Slayer 
The term "Big Bad" was originally used on American television program Buffy the Vampire Slayer (which aired 1997–2003). According to author Kevin Durand (2009), "While Buffy confronts various forms of evil during each episode, each season of Buffy the Vampire Slayer had its own 'big bad' villain who dominates throughout the season. The power of the 'big bad' always threatens to end the world, but Buffy ultimately overcomes him or her in the season finale."
The term was originally used in the episode "Bewitched, Bothered and Bewildered", in which Buffy Summers describes the newly soulless Angel as "the big bad thing in the dark". The phrase may originate in various fairy tales (particularly "Three Little Pigs" and the related song) about the "Big Bad Wolf". The phrase "big bad" by itself was first used on screen in Season 3, in the episode "Gingerbread" where Buffy says that an occult symbol is harmless, "not a big bad".
Season 1 
The first "big bad" villain on the program was The Master, played by Mark Metcalf. According to author Jan Jagodzinski, the battle between Buffy and the evil Master is "the central issue of season one"; The Master, like all the "big bads", is a "symptom of postmodernity". In the series' storyline, according to prophecy, the Master will kill the Slayer and bring Hell on Earth. While he succeeds in this task in the Season 1 finale "Prophecy Girl", he does not count on Buffy being resuscitated (after he bites her, she faints in a small pool of water and nearly drowns; she is revived a minute or so later by her friend Xander via CPR). Buffy's surprise revival allows her to defeat The Master.
Unlike other vampires who burst into dust completely upon being slain, the Master leaves behind a full skeleton. His bones are dug up in the Season 2 season premiere "When She Was Bad" in an attempt by a group of vampires at resurrection, but Buffy crushes his bones, killing him permanently.
Season 2 
With The Master dead, new "big bads" were introduced in season two of the program. Spike (played by James Marsters), Drusilla (played by Juliet Landau), and Angelus (played by David Boreanaz) become the new villains. Spike comes to Sunnydale in the episode "School Hard", accompanied by his longtime love Drusilla. Drusilla, in a weakened and frail condition, is cared for by Spike who hopes that the Hellmouth's energy will help to restore Drusilla's strength and health. They are soon reunited with Angel but constantly refer to him as Angelus (Angel's evil "alter ego").
Angelus was cursed with his soul a century before the events leading up to Season 2, but with one major stipulation: should Angelus (known as "Angel" when ensouled) experience even one moment of absolute happiness, the curse would be lifted, the soul removed, and Angelus would return. In the Season 2 episodes "Surprise" and "Innocence", Buffy and Angel have sex. Angel experiences perfect happiness, and his soul escapes his body, resulting in his transformation back to Angelus. He finds Spike and Drusilla in their warehouse headquarters and joins forces with them in their effort to destroy the Slayer. The storyline, according to author Jan Jagodzinski, raises "issues of love and abuse" while continuing the tradition of the "big bad".
In the two-part Season 2 finale "Becoming", Angelus's ultimate plan comes into view: by removing the sword from the Acathla statue, a portal to Hell will open up, sucking the world into it; only with Angel's blood can it be closed. After being double-crossed by Spike, Angelus removes the sword. Willow uses a spell to return Angel's soul. Even though Angel has returned, the gateway to Hell opens up. Buffy drives her sword into Angel's gut, sending him into the portal and closing it.
Season 3 
As evil as he is tidy and pleasant, Mayor Richard Wilkins (otherwise known as simply "The Mayor"), played by Harry Groener, was granted demonic properties in the 19th century. Since his founding of Sunnydale, he changed his name to Richard Wilkins, Jr., and then Richard Wilkins III, all to hide his inability to age. As part of the pact he made to keep himself demon, he was promised Ascension one day: a "promotion", of sorts, from partial demon to full demon. The Mayor is the first non-vampiric big bad to appear on the television program.
During the course of Season 3, he enlists the services of his vampiric associate Mr. Trick. After Trick is killed by the Slayer Faith (played by Eliza Dushku), she joins forces with him, essentially turning double-agent against Buffy. In "Graduation Day, Part Two", during a speech he is giving at the Sunnydale High graduation of the Class of 1999, his Ascension goes into full effect, transforming him into a giant serpent. Buffy lures the snake into the school library, which is fortified with TNT. She manages to escape and cue Giles, who obliterates the school, with the Mayor inside.
Season 4 
Adam (played by George Hertzberg) is a "biomechanical demonoid", a cyborg composed of multiple human and demon parts, reminiscent of Frankenstein's monster. Created by Professor Maggie Walsh, Adam is designed to be the ultimate life form - strong, immortal, and nearly omniscient through personal awareness and his ability to uplink with technology. Emotionless in tendency and personality, Adam is originally a loyal operative of the Initiative.
After being completed, Adam promptly kills Professor Walsh and immediately sets forth a plan of action - by summoning demons and putting them out in the open, The Initiative will imprison them. Once the prisons are full enough, he will override the security systems, freeing them all and forcing a battle between the demons and Initiative soldiers. From the bodies produced by the impending slaughter of both sides, he plans to create more cyborgs such as himself and build the ultimate army. Even though the battle takes place, Adam is killed by Buffy in "Primeval" by having his power source removed from his body. Adam is the first Big Bad to be defeated before the season finale; "Restless", the season four finale, focuses on the Scooby Gang's battle against the first Slayer, whose spirit they summoned to help them defeat Adam.
Season 5 
Glorificus, otherwise known as "Glory" (portrayed by Clare Kramer), unlike other monsters in the series, is not a demon but a god from a hell dimension. Banished to Earth (and forced to share a body with a human man named Ben), Glory's goal is to find a mysterious "Key", the only way to escape her banishment and return to her home dimension. However, The Key is not merely designed to open a magical portal: when activated it will simultaneously break down the barriers between every dimension in existence.
Unbeknownst to Glory, The Key is in the form of Dawn Summers, Buffy's younger sister who was created (not born) specifically for the purpose of hiding The Key; since Buffy is the Slayer and thus would make for a strong protector, an order of monks created Dawn and implanted false memories in everybody she would have ever met to hide the fact of her sudden appearance in their lives.
Once Glory finds out that The Key is in human form, she deduces that it is disguised as someone close to the Slayer, and someone new to the fold. Eventually, she kidnaps Dawn and takes her to a tower where the portal to her dimension will open, but the opportunity to use The Key is a small window and isn't for another few days. Ben later appears and tries to help Dawn escape but reconsiders when Glory promises to make Ben immortal on her return to her rightful divine state. Ben, who has lived his whole life knowing he would cease to exist (not merely die) should Glory regain her power, accepts this offer and betrays Dawn.
A few days later, as the opening is being prepared, Buffy shows up and Glory fights her. After a well-placed kick, however, she knocks off "her" head and reveals wiring - it's actually the Buffybot that Spike had ordered built as a sex toy but was reprogrammed by Willow. The real Buffy appears behind her and bloodies Glory as the ritual starts. Downed but not dead, Glory reverts back to Ben, whom Giles kills, thus killing Glory in the process.
Season 6 
The main villains in Season 6 were the Trio - Warren Mears (portrayed by Adam Busch), Jonathan Levinson (portrayed by Danny Strong) and Andrew Wells (portrayed by Tom Lenk) - followed by Willow (known in this phase as Dark Willow), portrayed by Alyson Hannigan. Series creator Joss Whedon stated on the Season 6 DVD that the true Big Bad was life itself, and how as time goes on, it becomes more and more people's worst enemy. In contrast to many other villains, the Trio are used mainly for comic effect. However, as the series progresses, they become more of a threat.
The Trio is a band of nerds who, over a game of Dungeons & Dragons, decide to take over Sunnydale. Recognizing Buffy as their biggest threat to their schemes, they attempt to keep her out of their hair and in the process get her seriously annoyed. Things get out of control, however, when after a failed attempt at turning Warren's ex-girlfriend Katrina into their love slave, Warren accidentally kills her as she tries to escape and inform the police. This takes the three characters into separate character paths—Warren becomes misogynistic and assumes the role of leader of the Trio, Jonathan lets his conscience take over and grows in disdain for Warren, and Andrew becomes increasingly loyal to Warren. The Trio plan a series of bank heists using powerful artifacts that grant immense strength and invulnerability. Unknown to Jonathan, Warren and Andrew plan to escape leaving him to be arrested. In the end however, after a confrontation with Buffy, both Jonathan and Andrew are sent to jail while Warren abandons them and escapes.
After another caper is foiled by Buffy, Warren decides to remove her for good. He acquires a gun and shoots at Buffy, injuring her, while a stray bullet hits Tara, killing her almost instantly. Willow, who has been recovering from an addiction to dark magic, tries to resurrect Tara as she did Buffy but cannot because the death was not by mystical means and thus Tara was "taken by natural order". Now obsessed with vengeance, Willow resumes using magic and quickly begins to lose herself in the dark power. After discovering that he didn't kill the Slayer, Warren attempts to escape but is soon caught and flayed alive by Dark Willow.
After Warren's death, Willow goes after the two remaining members of the Trio, but Buffy, Xander and Anya break them out of jail. Willow becomes lost to dark magic and despair; she is confronted by Buffy and the two of them fight. In the middle of the battle, Giles appears, returning from England. Giles enters the battle and is gravely injured; Willow begins draining the magical power out of him. However, this was in fact Giles's plan: the magic he was channeling was not the dark power Willow had been drawing on, but a kind of magic that comes from humanity. This infusion of light magic allows Willow to feel again, expanding her empathy so she can feel the emotions of practically everyone. However this seems to backfire, as in her grief and depression she decides to destroy the world to put an end to everyone's suffering.
Buffy saves Andrew and Jonathan from being killed and the pair decide to flee to Mexico. On a bluff on the other side of Sunnydale, Willow uses her magic to raise an ancient satanic temple from the ground and begins chanting, but Xander arrives and tries to trigger her emotions. Even though Willow keeps knocking him down, Xander repeatedly tells her that he loves her. Eventually, the emotion in Willow is too much and the dark magical power in her fades away as she and Xander break down in tears, embracing.
Season 7 
The First Evil is uniquely portrayed by many actors and many characters. The First is incorporeal, but it has the ability to take the form of anyone who has died, even if the person is still active in some way, such as Buffy, or a vampire; through skillful playacting it can impersonate a living person. The First appears to possess all the knowledge of the form it has taken. Through the aid of rituals performed by its Harbingers, it also has the ability to appear in dreams. Finally, it also has the ability to imbue certain rare beings with its powers. Its first appearance is in the Season 3 episode "Amends". Through impersonating Angel's victims and manipulating his dreams, it attempts to convince him to kill Buffy. This failing, it manipulates him into trying to commit suicide. Had it succeeded, this would have been a powerful blow to the forces of good. However Buffy defeats The First's Harbingers and The First vanishes, promising to return.
Since The First is non-corporeal, it can't be killed. But since it can't touch anything, it can't kill, at least directly. When Buffy was brought back from the dead at the beginning of Season 6, however, this caused an instability in the source of the Slayer's power. This created the opportunity for the first to attempt to destroy the Slayer Line in its entirety. It enlists the services of Caleb (played by Nathan Fillion), a misogynistic preacher, who commanded the Bringer army—Harbingers who were ordered to kill those who were in line to become the next Slayers, should the current ones die. It was part of a master plan that, if successful, would solidify The First as a physical entity. By working backwards, killing all the potential Slayers, followed by the current Slayer, nothing would exist to stop The First from flooding the world with an army of Turok-Han, a breed of supervampires (known in the series as übervamps), shifting the scale of the world irrevocably in favor of evil and making The First corporeally manifest.
To do this, however, the Hellmouth had to be opened. Buffy and an army of potential Slayers used their blood to open the Seal of Danzalthar, thus opening the Hellmouth. After an epic battle between the Turok-Han and the Potentials/Scoobies, the Turok-Han were defeated (though not without casualties) by a special amulet given to Spike by Buffy, by way of Angel. The amulet channeled the power of sunlight and killed the entire Turok-Han army. Thus, the Big Bad of one series contributed significantly to the defeat of the Big Bad of another series. The amulet also acted as a purifying force, powerful enough that it closed the Hellmouth. This caused all of Sunnydale to collapse into a massive sinkhole. Though The First was not destroyed, its plans were thwarted and without the Hellmouth it was unable to raise a demon army.
Season 8 
Although the television series ended with season seven, series creator Joss Whedon devised a comic book series that continued the story beyond the seventh season.
Twilight is revealed in part four of "No Future For You". He can fly, has superhuman strength, and believes that the newly-created Slayer army is no better than a pack of demons. His main aim is the total eradication of all magic, both good and evil. His minions include former Sunnydale residents Amy Madison, Warren Mears and Riley Finn alongside the late Irish warlock Roden, British Slayer Lady Genevieve Savidge and American General Voll. Eventually it was spoilered by comics cover and later confirmed that Twilight is Angel. His Twilight persona was in fact a ruse designed to distract the members of the anti-Slayer movement most likely to attack, thus limiting the potential destruction that would have been caused if those factions struck independently while trying to keep the deaths of the Slayers to a minimum, all while he pushes Buffy towards some unknown goal.
In other series 
- The short-lived series Birds of Prey actually used the term "Big Bad" on screen to refer to Harley Quinn.
- The final scene of Stargate: The Ark of Truth featured Lt Col Cameron Mitchell stating that it was strange not to have a "big bad" to face any more following the removal of both the Ori and Goa'uld threats.
- In the May 11, 2007 Lost podcast, the show's producers refer to Ben Linus as the series' "Big Bad", although they have subsequently revealed, and demonstrated, that Charles Widmore is even worse. In the final season however, even Widmore appears heroic when set up against the Man in Black.
- Even comics have adopted the term into their lexicon, with Nightwing describing Bruno Mannheim to Batwoman as "the Big Bad" in DC Comics' 52: Week 30.
- In the Bones (TV Series) episode, "The Widow's Son in the Windshield", Booth, portrayed by David Boreanaz, states that the Gormogon killer is "big and bad", a probable reference to his tenure on Buffy.
Similarly, in Veronica Mars, there is a Big Mystery revolving around a crime perpetrated by the Big Bad of the season. Greg Weisman, a fan of Joss Whedon's, described Demona as a "Big Bad" in issue three of the Gargoyles comic book. Sara Colleton, executive producer for Dexter, referred to that show's use of a main villain for each season as the "Big Bad formula". In an interview with Television Without Pity, Chuck showrunner Chris Fedak mentioned that Alexei Volkov was Season 4's Big Bad.
- Since its revival Doctor Who has had a Big Bad every Series. Series 1 it was the Daleks. Series 2 it was the Cybermen, later the Daleks became involved. Series 3 it was renegade Time Lord the Master (Doctor Who). Series 4 it was again the Daleks. For Series 5 it was possibly the Silence (Doctor Who), though they did not fully appear till Series 6, where they again took the Big Bad role. The Great Intelligence took the Big Bad role for Series 7. Series 7 In the Classic Series there were already Big Bads however. In Season 8 it was the Master, who made alliances with such creatures as the Nestenes and Axos. Season 16, the Key to Time arc, could be seen as having a Big Bad, the Black Guardian, though he and his servant only appeared in the final serial.
- MacNeil, W.P. (2003). "You Slay Me: Buffy as Jurisprude of Desire". Cardozo Law Review, Vol. 24(6), pp. 2421-2440.
- Brannon, J.S. (2007). "It's About Power: Buffy, Foucault, and the Quest for Self". Slayage, v. 24.[not in citation given]
- Durand, Kevin K. (2009). Buffy Meets the Academy: Essays on the Episodes and Scripts as Texts. McFarland. p. 59. ISBN 978-0-7864-4355-0.
- Jagodzinski, Jan (2008). Television and youth culture: televised paranoia. Palgrave Macmillan. p. 145. ISBN 1-4039-7808-5.
- Phegley, Kiel (January 8, 2009). "Behind Buffy's Twilight Reveal". Comic Book Resources. Retrieved January 9, 2009.