History Main / JekyllAndHyde

* ''{{Anime/Bakugan}}'': [[spoiler:[[TheHeavy Masquarade]] is revealed to actually be ''Alice,'' the FriendToAllLivingThings and NiceGirl of the main team. The JekyllAndHyde complex was created due to being around her [[MadScientist grandfather]]'s laboratory at the time of an experiment that released powerful negative energy into the area. Masquarade is a cruel, sadistic, and incredibly powerful and strategic Brawler that plagues the main cast constantly, Alice is a [[NonActionGuy Non-Action Girl]] {{Pacifist}} that wishes avoid fighting altogether. This is also a case of GenderBender. By the end, the [[TomatoInTheMirror truth is revealed to her]], and she is driven to abandon her team for fear of turning into Masquarade at inopportune times. Ultimately, a SplitPersonalityMerge occurs. Masqurade instead manifests himself occasionally as a SpiritAdvisor in Brawling to Alice, who finally becomes an ActionGirl (while still keeping her NiceGirl personality).]]

* ''Film/DrJekyllAndMsHyde'', itself a Comedic Remake of the darker ''Dr Jekyll and Sister Hyde'', parodies the trope, with meek scientist Richard Jacks turning into a lustful, cutthroat [[GenderBender female alter ego]] named Helen Hyde via a recreation of his ancestor Henry Jekyll's formula.

Sometimes, though, the “Hyde” is not really [[DarkIsNotEvil evil; it may just be more instinctual or capable of using violence when necessary]]... See DrPediaAndMrTrope for the {{Wiki Trope|s}} version of this. Also, a "Jekyll" persona isn't necessarily entirely "good" either — it may just be subtler or more self-controlled. After all, in the original story, Jekyll created Hyde as an outlet for his darker impulses. Occasionally, the situation can be resolved (not necessarily favorably) with a SplitPersonalityTakeover, or with a SplitPersonalityMerge that reconciles both sides into a healthy whole.

The trope name comes, of course, from ''Literature/TheStrangeCaseOfDrJekyllAndMrHyde'', by Creator/RobertLouisStevenson. The reveal was originally a TwistEnding in the case of that story, but the book became famous and now it [[AllThereIsToKnowAboutTheCryingGame no longer surprises anyone]]. Most adaptations of the work focus on said twist. Other occurrences of the trope may still manage to surprise, if they’re well done.

The real life example of [[http://en.wikipedia.org/wiki/Deacon_Brodie Deacon Brodie]] (cabinet-making pillar of the church by day, burglar by night) is said to have inspired Stevenson, as did the story of [[https://en.wikipedia.org/wiki/Horace_Wells Horace Wells]], a pioneer of medical anesthetics. While researching chloroform by [[ProfessorGuineaPig testing various dosages on himself]], Wells unknowingly built up a dangerous level of the drug in his system, and ultimately attacked two prostitutes with sulfuric acid in a state of intoxicated paranoia. He then committed suicide after sobering and learning of what he had done.

** Harvey Dent, a.k.a 'ComicBook/TwoFace' has this going on as well, with the split represented by Harvey's own [[TwoFaced split face]]; his unblemished, handsome right side representing the good, noble District Attorney Harvey Dent, and the scarred, mangled left side representing the malevolent, vicious criminal Two-Face. In his case, the choice between 'Jekyll' and 'Hyde' depends on the results of a coin toss, with good or bad triumphing depending on which side the coin comes down on. This is singly most obvious in his debut appearance, where distinct similarities are drawn between him and the story. In fact, his appearance was inspired by [[http://about-faces.livejournal.com/6931.html a poster for the Spencer Tracy film]].

* Bruce Banner and his more famous dark side the ComicBook/IncredibleHulk. This has been played with many times over the years, with Hulk varying from a brutal monster to an innocent savage. For a while between ''ComicBook/WorldWarHulk'' and ''Hulk: Agent of S.H.I.E.L.D.'', Banner was portrayed as ''Hulk's'' dark side, since [[spoiler: unlike Hulk, he'd actually killed someone]]. And in the ''ComicBook/{{Marvel 1602}}'' {{Elseworld}}, David Banner gets transformed into the Incredible Hulk. Lord Banner works as an enforcer for [[UsefulNotes/TheHouseOfStuart James VI of Scotland and I of England]], and is evil, sadistic and altogether not a nice bloke at all. Follow-ups reveal that the Hulk, on the other hand, is noble and intelligent. (And his influence eventually redeems Banner.)

* The Creator/AmicusProductions version, ''Film/IMonster'' followed the original novel quite closely but changed the characters' names in the hope of catching the viewers by surprise.

* ''[[GenderBender Dr Jekyll and Ms Hyde]]'', itself a Comedic Remake of the darker ''Dr Jekyll and Sister Hyde''.

* [[Film/TheNuttyProfessor1963 Julius Kelp]] (Sherman Klump in [[Film/TheNuttyProfessor1996 the remake]]) and Buddy Love in ''The Nutty Professor'', as a more family-friendly variant; Dr. Klump is a nebbish with virtually no social graces, while his alter ego Buddy Love is a casanova who oozes with charisma.

* ''Film/OtherHalves'' is about an dating app that creates that unleashes the user's "other half," or id.
* ''Film/DrJekyllAndMsHyde'': Parodied, with meek scientist Richard Jacks turning into a lustful, cutthroat female alter ego named Helen Hyde (via a recreation of his ancestor Henry Jekyll's formula).

Sometimes the “Hyde” is not really [[DarkIsNotEvil evil]], though... see DrPediaAndMrTrope for the {{Wiki Trope|s}} version of this. Occasionally, the situation can be resolved (not necessarily favorably) with a SplitPersonalityTakeover, or with a SplitPersonalityMerge that reconciles both sides into a healthy whole. Also, a "Jekyll" persona isn't necessarily entirely "good" either — it may just be subtler or more self-controlled.

Sometimes the “Hyde” is not really [[DarkIsNotEvil evil]], though... see DrPediaAndMrTrope for the {{Wiki Trope|s}} version of this. Occasionally, the situation can be resolved (not necessarily favorably) with a SplitPersonalityTakeover, or with a SplitPersonalityMerge that reconciles both sides into a healthy whole. Also, the "Jekyll" side isn't necessarily entirely "good" either — it may just be subtler or more self-controlled.

If the two personalities are aware of each other, this becomes a case of GollumMadeMeDoIt. For a more mundane version, see MoodSwinger. See InVinoVeritas if the change is alcohol-induced (you could call it "Dr Jekyll and Mr Jack Daniels"). As a “Hyde” personality's crimes are outside the “Jekyll’s” control and the “Jekyll” is usually unable to stop the “Hyde” emerging, this is often a case of being DrivenToVillainy.

Sometimes they're not really [[DarkIsNotEvil evil]], although ... see DrPediaAndMrTrope for the {{Wiki Trope|s}} version of this. Occasionally, this can be resolved (not necessarily favorably) with a SplitPersonalityTakeover, or with a SplitPersonalityMerge that reconciles both sides into a healthy whole. Also, the "Jekyll" side isn't necessarily "good" either.

Comes, of course, from ''Literature/TheStrangeCaseOfDrJekyllAndMrHyde'', by Creator/RobertLouisStevenson. It used to be a TwistEnding, but it [[AllThereIsToKnowAboutTheCryingGame no longer surprises anyone]]. Most adaptations of the work focus on said twist.

If the two personalities are aware of each other, it becomes a case of GollumMadeMeDoIt. For a more mundane version, see MoodSwinger. See InVinoVeritas if the change is alcohol-induced (you could call it "Dr Jekyll and Mr Jack Daniels"). As the Hyde personality's crimes are outside the characters’ control and, often, the characters are unable to stop themselves from becoming evil, this is often a case of being DrivenToVillainy.

If the two personalities are aware of each other, it becomes a case of GollumMadeMeDoIt. For a more mundane version, see MoodSwinger. See InVinoVeritas if the change is alcohol-induced (you could call it "Dr Jekyll and Mr Jack Daniels"). As the Hyde personality's crimes are outside the character's control and, often, the character is unable to stop themselves from becoming evil, this is often a case of being DrivenToVillainy.

* In the iOS game ''VideoGame/LaytonBrothersMysteryRoom'', [[spoiler: Alfendi]] is in this predicament thanks to an incident 4 years ago. However, it seems that the [[spoiler: "Hyde"]] is the really personality while his new persona is the [[spoiler: Jekyll]].

Jekyll Jekyll Hyde! Jekyll [[WesternAnimation/{{Arthur}} Hyyyyyyde!]]''

* In ''All-Star Comics'' #20, the ComicBook/{{JSA}} are helping industrialist Jason L. Rogers track down a criminal known as "The Monster", a hideous-looking man who follows Rogers around and has cost him his family and his business. It turns out that Rogers himself turns into "The Monster" and never knew it.

[[folder:Web Comics]]

* [[spoiler:It seems that Ples Tibenoch]] of Tessa Stone's ''Webcomic/HannaIsNotABoysName!'' has a Jekyll and Hyde disorder of sorts.

* In the manga ''Manga/SixSixSixSatan'' (or ''O-Parts Hunter'' in the US), the main character Jio has Satan inside of him. Satan comes out when Jio's or his friend's lives are threatened. [[spoiler:That is, until the time skip. By the end, it's revealed that Jio is Satan reborn. Jio is ''Satan's'' dual personality.]]

* The eponymous character of ''WesternAnimation/{{Kaeloo}}'', who is normally a [[NiceGirl cute, gentle]] frog, transforms into a [[HulkingOut huge, buffed]], {{Sadistic}} toad whenever she gets angry. Some episodes imply that she knows what she's doing, but others imply that she has no control over this.

* Bruce Banner and his more famous dark side the ComicBook/IncredibleHulk. This has been played with many times over the years, with Hulk varying from a brutal monster to an innocent savage. For a while between ''ComicBook/WorldWarHulk'' and ''Hulk: Agent of S.H.I.E.L.D.'', Banner was portrayed as ''Hulk's'' dark side, since [[spoiler: unlike Hulk, he'd actually killed someone]].
** In the ''ComicBook/{{Marvel 1602}}'' {{Elseworld}}, David Banner gets transformed into the Incredible Hulk. Lord Banner works as an enforcer for [[UsefulNotes/TheHouseOfStuart James VI of Scotland and I of England]], and is evil, sadistic and altogether not a nice bloke at all. Follow-ups reveal that the Hulk, on the other hand, is noble and intelligent. (And his influence eventually redeems Banner.)

** The Green Goblin is sometimes, and to an extent originally, depicted as a split personality of the milquetoast scientist ComicBook/NormanOsborn. The main difference is that Osborn is a ManipulativeBastard, while the Goblin is an AxCrazy psychopath. Since he came BackFromTheDead, Osborn had been more or less in control and became the Goblin willingly and [[ForTheEvulz for shitz and giggles]], but recently he's started losing it again.
*** When he had a breakdown at the end of ''Dark Reign'' after being (to the public) the squeaky clean Iron Patriot, when they took his mask off he had Green Goblin paint on underneath... (though in that case, that might have been triggered by [[ComicBook/XMan Nate Grey]], who'd planned to cut the Goblin persona loose from deep within Osborn and show the world what he really was. While Nate lost that round, it looks like he won the war).

* In the ''Franchise/{{Transformers}}'' universe, the Autobot Punch adopted a Decepticon personality as Counter-Punch, so as to play a double agent. He has lost some sense of self-identity because the Counter-Punch personality takes over, leaving him with a sense that he's missed out on the past hour or so.

* Several times in ''WesternAnimation/JackieChanAdventures'' is Jackie split into a good and bad side, usually via the Tiger talisman. These two sides are the same person and represent the balance in all humans of a good and bad side. Ironically, this occurs in one episode in which Jade is performing in a play about Jekyll and Hyde.
** It's not really "good" and "bad" so much as "moral pacifist" and "amoral badass":
-->'''Jade''' (pointing to amoral Jackie): You're evil! EVIL!
-->'''Uncle''': Not evil. Only misguided.

* Morph from the ''WesternAnimation/XMen'' animated series, after coming BackFromTheDead, often wavered back and forth between his normal, "Jekyll" self and a semi-undead "Mr. Hyde" alter-ego who blamed the X-Men for leaving him behind on a failed mission. It turned out he was [[BrainwashedAndCrazy mind-controlled]] by the season's BigBad, but the effects didn't leave him for a good while afterward.
** At one point, he even hides out with a theater troop, where he performs "Jekyll and Hyde", using his [[VoluntaryShapeshifting shapeshifting]] powers to play both roles.

* The ''WesternAnimation/{{Beetlejuice}}'' episode "Dr. Beetle And Mr. Juice" has B.J. creating a perfume that has a weird effect--it turns whoever applies it into their opposite personae. When it accidentally hits Lydia, she turns from being sweet and introverted into an obnoxious prank-playing biker.
** There was another episode where Beetlejuice briefly visited a doctor in the Neitherworld whose Jekyll self was patient in getting Beetlejuice to cooperate, but would turn into Hyde when BJ started to get on his nerves.

* It must have been Creator/FrizFreleng's favorite book, because he did three or four cartoons on the theme for Warner Bros., and a couple more at Depatie-Freleng Enterprises, specifically

* ''Anime/{{Gankutsuou}}'' has Literature/TheCountOfMonteCristo possessed by the titular demon which completely submerges his original good personality as Edmond Dantes.
** This is only a part of the story, as it was Edmond's own lust for revenge that summoned Gankutsuou to him, to begin with, and Gankutsuou has no personal interest in doing any harm to Edmond's enemies or their loved ones, only fulfilling his own end of the bargain. When it seems that Gankutsuou has fully consumed Edmond, he simply walks away from the person he was about to kill as revenge by proxy, without so much as looking back.

* In ''Manga/DGrayMan'', this is the case with Tyki Mikk and quite possibly the rest of the Noah.
** Nah, just Tyki (who 'loves humans'); but his mind remains constant between sides, and he gave his little friend the silver off a murdered exorcist's coat as a present. If Allen ''had'' gotten it, the plot might have run a bit differently....
** Also, White Tyki appears to be effectively dead. His identity took a serious scramble back when Allen thought he'd cut the evil out of him and got a ''[[SuperPoweredEvilSide really ]]''[[SuperPoweredEvilSide superpowered ]]''[[SuperPoweredEvilSide especially ]]''[[SuperPoweredEvilSide evil side]] instead. Surprising pulled himself back together, but he's different.
** The Noah are activated out of normal humans, whenever a seat is left unfilled by a death in the family, and for the most part memory is not continuous from incarnation to incarnation, but those persons are still subsumed into the Noah identity once activated. [[spoiler: This is one of the things Allen is trying to prevent happening to him.]]
*** Whether [[BigBad Adam the Millennium Earl]] and the Fourteenth have died and recorporated before is not clear; very possibly they haven't. Road is over thirty five now; it's possible Adam has kept that rakish young face for thousands of years. (And covered it with a grinning balloon thing in a goofy hat about as long. Mysteriously.)

** Harvey Dent, a.k.a 'ComicBook/TwoFace' has this going on as well, with the split represented by Harvey's own [[TwoFaced split face]]; his unblemished, handsome right side representing the good, noble District Attorney Harvey Dent, and the scarred, mangled left side representing the malevolent, vicious criminal Two-Face. In his case, the choice between 'Jekyll' and 'Hyde' depends on the results of a coin toss, with good or bad triumphing depending on which side the coin comes down on.
*** This is singly most obvious in his debut appearance, where distinct similarities are drawn between him and the story. In fact, his appearance was inspired by [[http://about-faces.livejournal.com/6931.html a poster for the Spencer Tracy film]].

* In ''ComicBook/{{Daredevil}}'', Typhoid Mary is the split personality of the otherwise nice and peaceful Mary Walker. She also has the Bloody Mary personality.

* [[spoiler:The protagonist and Tyler Durden]] from ''Film/FightClub''.
** [[LampshadeHanging Lampshaded]] by Marla: "You're Dr. Jekyll and Mr. [[JerkAss Jackass]]."
* ''[[GenderBender Dr Jekyll and Ms Hyde]]''.
** Itself a Comedic Remake of the darker ''Dr Jekyll and Sister Hyde''.

* Brainwashed Geordi used as an assassin on ''Series/StarTrekTheNextGeneration''.

** ''Series/StarTrekTheOriginalSeries'' with "The Enemy Within", where a transporter malfunction splits Kirk's good and evil sides.

* ''Series/BuffyTheVampireSlayer''. [[spoiler:The BigBad of Season 5 is Glory, a female PhysicalGod imprisoned within the body of Ben, a male human. Although Glory is the more powerful personality, Ben is still able to hamper her to some degree. In the season finale, the distinction between them starts to break down, with Glory beginning to feel genuine human emotions (like sympathy, guilt, and fear) and Ben becoming more callous and self-serving (like being willing to cooperate with Glory's plan in order to survive himself). Eventually they are able to switch back and forth rapid enough to actually talk to each other]]
** More obvious, Angel and Angelus from ''Series/BuffyTheVampireSlayer'' and ''Series/{{Angel}}''. Though at different times in both series that varies between Jekyll & Hyde and EnemyWithin. It all depends on whether Angel simply becomes evil when he loses his soul (as his Series/{{Buffy|the Vampire Slayer}} appearances and Series/{{Angel}}'s fifth season implied) or if losing his soul replaces Angel with the demon soul of Angelus (as it seemed to be in Series/{{Angel}}'s fourth season).
*** Except that Angel losing his soul always leads to the demon Angelus taking over, because Angelus is always there. Otherwise Angel would, at least, not be able to vamp out, and probably keel over dead, being a corpse, without the demon animating him. For proof, see the season 2 finale of Angel. When he tries to vamp out on Pylea, [[spoiler:the demon takes over completely and is a mindless, inhuman monster]]. Angelus, particularly according to that example, is a blend of the demon's personality and sadism with Angel's memories and brain (but not his soul). When Angel loses his soul, it's gone, and all that's left is Angelus. ''All'' of those incidents where he's evil ''are'' Angelus.

* [[Series/{{Smallville}} Davis Bloome]]/Doomsday.

** A Similar example are the villains [[TheChessmaster Heckyl]] and [[TheBrute Snide]] from ''Series/PowerRangersDinoCharge''. Played with, however, in that both personalities are firmly evil, just preferring different methods and disdaining the other's. Towards the end, Heckyl has a HeelFaceTurn, and Snide uses some tech to [[LiteralSplitPersonality completely separate them]].
* ''Series/TheVampireDiaries'': Stefan Salvatore. He has one side of his personality which is kind, caring, empathetic and compassionate and heroic ("Jekyll", Hero!Stefan) and another side of his personality which is sociopathic, crazy, addictive, cold and ruthless ("Hyde", Ripper!Stefan)

* The main hook of ''Do No Harm'': The title character is an ethical doctor who switches to a malevolent second personality at 8:25 pm each night and then reverts back at 8:25 am the following morning. After keeping this personality sedated with drugs for years, one day he finds that his body has become immune to them...unleashing the other personalty, now bent on destroying his life. [[spoiler: [[SubvertedTrope Subverted]] in the series finale when it was [[TheReveal revealed]] that the benevolent personality was in fact the actual alter while the malevolent one was the original]].

* The first 5 Albums of ''ASP'' tell the story of the Black Butterfly, a vampire-like entity, which sometimes seems to inhabit the body of the protagonist. For example, in the song ''Lykanthropie (Es tobt ein Krieg in mir)'', it's compared to werewolves, with the protagonist not remembering what he did while under the creatures influence.
** Also, in promotional shots, both the protagonist and the Black Butterfly are represented by the bands lead singer Alexander Spreng.

* Jackson Jekyll and Holt Hyde from ''Toys/MonsterHigh''. Unsurprisingly.
** Somewhat subverted in that neither of them are evil. Jackson is a rather sweet, quiet, studious boy, whereas his alter ego is louder and more boisterous but still has a good heart. Granted, Holt Hyde is a [[CuteMonsterBoy monster]], but considering the setting that is a compliment.

* When [[spoiler:Gamzee Makara]] of ''Webcomic/{{Homestuck}}'' is stoned, he's one of the sweetest, most goofy LoveFreak characters in the whole thing. [[BewareTheSillyOnes But]] [[AxCrazy when]] [[MonsterClown he]] [[OmnicidalManiac gets]] [[NoMedicationForMe sober...]]

* This is how [[WebVideo/TheSpoonyExperiment Spoony]] and [[MadScientist Dr. Insano]] are portrayed in the Website/ThatGuyWithTheGlasses anniversary special ''WebVideo/{{Kickassia}}''. (This is subject to NegativeContinuity.)
** NegativeContinuity indeed. [[spoiler: ''WebVideo/ToBoldlyFlee'' had retconned this into an anomaly caused by the PlotHole, in 'reality', Spoony and Insano are indeed two separate people.]]

* ''Literature/TheStrangeCaseOfDrJekyllAndMrHyde'', which is the TropeNamer, gives us the [[UnbuiltTrope unbuilt variant of this dynamic]]. Henry Jekyll is a good man with evil urges who deliberately created a potion to turn himself into Edward Hyde for a selfish purpose and, up until a murder was committed, derived pleasure from his darker self's actions. However, eventually he started changing even without the potion, and had to create a new one to ward off Hyde taking control. Recreating the formula proved impossible, and he wrote a letter to explain everything before dying. The idea of Jekyll and Hyde being the same individual was originally a TwistEnding; the reason for almost all adaptations removing this aspect is that the twist eventually became well-known.

* ''ComicBook/GreenLantern'':
** Kyle Rayner's vast powers were not being fully harnessed, so they formed a shadow entity called Oblivion.
** Hal Jordan had an arc where his...conjured body was warping between Spectre, the white-templed Evil Hal run by the fear entity Parallax, which is what he looked like when he did the genocide thing, and his own mixed-up personality, which looks like he did when he was a spry young pilot and at the top of his superheroing game. Often the head and shoulders of one entity will come thrusting out of one of the others. It verges on [[{{Squick}} squicky]]. They argue a lot. Specter only possessed Hal hoping he could purge Parallax, but now it looks like Parallax might just be getting the Specter's considerable powers, and the Specter and Hal can't see eye-to-eye enough to work well together.
*** Ultimately Parallax is overwhelmed, the Spectre [[BlueAndOrangeMorality ditches Hal to go find another host]] just when it looked like they could really beat Parallax, the remaining two split, and Hal winds up back in his body (which had been preserved where he sacrificed himself in the sun), which de-ages to match the look of his soul, and he's a good guy again. Just in time for the world to go to hell.