History Main / JekyllAndHyde

* AlphaFlight's Aurora switched between a free-spirited superhero personality and that of a highly repressed Catholic school teacher.
* [[GreenLantern Kyle Rayner]]'s vast powers were not being fully harnessed, so they formed a shadow entity called Oblivion.

* ''Anime/AmuriInStarOcean'' has Perrier/Vernier La Mer. Perrier is the real personality who, as a result of torturously cruel parenting, subconsciously created Vernier as a defense mechanism and referred to her as her older sister. When seeing her reflection, Perrier would see Vernier looking back and talking to her, always taunting and insulting her. Vernier does not take full control of Perrier, though, until she is pushed into a state of extreme terror.

* ''Amuri in Star Ocean'' has Perrier/Vernier La Mer. Perrier is the real personality who, as a result of torturously cruel parenting, subconsciously created Vernier as a defense mechanism and referred to her as her older sister. When seeing her reflection, Perrier would see Vernier looking back and talking to her, always taunting and insulting her. Vernier does not take full control of Perrier, though, until she is pushed into a state of extreme terror.

** This is only a part of the story, as it was Edmond's own lust for revenge that summoned Gankutsuou to him, to begin withm, 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.
* Tohno Shiki from ''{{Tsukihime}}''; when either his life is in extreme danger or he is confronted with something non-human he loses grip on his consciousness and becomes the [[SuperpoweredEvilSide amoral sociopathic killer]] Nanaya Shiki, who is a ''highly'' skilled assassin. Slightly subverted, though, in that [[spoiler:despite being the main personality, Tohno Shiki is the false, created identity while Nanaya Shiki is the 'original' (yet Nanaya rarely ever appears). Nanaya is the Shiki who would have been, had his clan not been wiped out during his childhood and him hypnotized and brainwashed later on into becoming Tohno Shiki.]]

* In ''DGrayMan'', this is the case with Tyki Mikk and quite possibly the rest of the Noah.

* Naraku and his evil human self, Onigumo, in ''{{Inuyasha}}''.

* Angel Starr from the first ''AceAttorney'' game, complete with PeekABangs moving from one eye to another depending on whether she's sweet or sour.

* In {{Bioshock Infinite}} [[spoiler:Booker and Comstock are the same person.]] In the beginning it's more of an Evil Twin situation - they do not actually "merge" like for example [[spoiler:dead Chen Lin and living Chen Lin]]. Metaphorically, though, [[spoiler:Comstock]] is the evil within [[spoiler:Booker - both are single-minded, cynical and have a high capacity for violence. Booker is also willing to committ massive manslaughter and serve blatant lies to reach his goal (which in the beginning of the game is even quite morally corrupt).]] Later on, the metaphor becomes physical reality. Firstly, [[spoiler:when Booker kills Comstock but is forced to take charge of the Hand of the Prophet and use the Songbird to destroy a Vox Populi attack. Temporarily, he is Comstock in both biology and social function.]] Secondly [[spoiler:when he is transferred back in time to actually merge with the earlier version of himself that is set on the path of becoming Comstock. When this past Booker "remembers" his future actions as the Hyde, he chooses to let himself be killed. The hero has, indeed, "caught himself".]]

** It also happened in ''WesternAnimation/BeastMachines'', with Savage and Noble. Savage is a blind, insane, vicious dragon, while Noble is an intelligent and cunning [[{{Wolfman}} wolfbot]].

* The quevari, a human subspecies from the {{Ravenloft}} setting, live as benign vegetarian pacifists by day, but become bloodthirsty killers by night.

[[/folder]]

* In {{Bioshock Infinite}} [[spoiler:Booker DeWitt and Zachary Comstock is the same person.]] In the beginning it's more of an Evil Twin situation - they do not actually "merge" like for example [[spoiler:dead Chen Lin and living Chen Lin]]. Metaphorically, though, [[spoiler:Comstock]] is the evil within [[spoiler:Booker - both are single-minded, cynical and have a high capacity for violence. Booker is also willing to committ massive manslaughter and serve blatant lies to reach his goal (which in the beginning of the game is even quite morally corrupt).]] Later on, the metaphor becomes physical reality. Firstly, [[spoiler:when Booker kills Comstock but is forced to take charge of the Hand of the Prophet and use the Songbird to destroy a Vox Populi attack. Temporarily, he is Comstock in both biology and social function.]] Secondly [[spoiler:when he is transferred back in time to actually merge with the earlier version of himself that is set on the path of becoming Comstock. When this past Booker "remembers" his future actions as the Hyde, he chooses to let himself be killed. The hero has, indeed, "caught himself".]]

* In the ''{{Neptunia}}'' series, [=CPUs=] are a mild example. While there's only one consciousness and they retain all their memories, goals, ect. during the voluntary transformation, their normal and [[SuperMode Hard Disk Divinity]] forms can have very different personalities. TheSlacker Neptune's HDD form is a more mature LadyOfWar is one example. Another is Plutia, who goes from a friendly, scatterbrained girl to a [[BastardGirlfriend stone-cold]], [[TheDreaded ally-terrifying]] {{Dominatrix}}.
[[/folder]]
* A key plot point of {{Bioshock Infinite}}, but the explanation is all spoilers: [[spoiler:Booker DeWitt and Zachary Comstock is the same person. At first, this is not formally "Jekyll and Hyde" situation but more of an Evil Twin situation: they do not inhabit the same body. They are the same person from different realities, and their bodies and minds apparently resist the "merging" of identical persons better than, say, the unfortunate Chen Lin (who actually merges with his dead counterpart from another reality - with horrible results). At a metaphorical level, though, it really is a Jekyll and Hyde situation: Booker has quite a bit of Comstock's villainy in himself - he is single-minded, cynical and has a high capacity for violence. To get his goal, which he himself initially believes to be less than noble, Booker is willing to committ massive manslaughter and serve blatant lies. Sounds familiar? The main difference is that Booker is self-conscious about his vices, not born-again and "in love with himself", as he says Comstock is. Later on, the "Jekyll and Hyde" situation transcends metaphor and becomes reality. When Booker at the end of the game kills COmstock, he is forced to take charge of the Hand of the Prophet and use the Songbird to destroy a Vox Populi attack - biologically, he is now the only Comstock around, and he is fulfilling Comstock's function. Immediately afterwards, Booker undoes Comstock's creation, but this does not stop the Jekyll from ever having existed. Booker is transferred back in time and actually merges with an earlier version of himself that is set on the path of becoming Comstock. The whole game has put our Jekyll and Hydes on a path towards an eventual merger into one body, in order for Jekyll to be "smothered in his crib" by a regretful Hyde.]]

* {{Bioshock Infinite}}, but the explanation is all spoilers: [[spoiler: Booker DeWitt and Zachary Comstock is the same person. At first, this is not formally "Jekyll and Hyde" situation but more of an [[Evil Twin]] situation: they do not inhabit the same body. They are the same person from different realities, and their bodies and minds apparently resist the "merging" of identical persons better than, say, the unfortunate Chen Lin (who actually merges with his dead counterpart from another reality - with horrible results). At a metaphorical level, though, it really is a Jekyll and Hyde situation: Booker has quite a bit of Comstock's villainy in himself - he is single-minded, cynical and has a high capacity for violence. To get his goal, which he himself initially believes to be less than noble, Booker is willing to committ massive manslaughter and serve blatant lies. Sounds familiar? The main difference is that Booker is self-conscious about his vices, not born-again and "in love with himself", as he says Comstock is. Later on, the "Jekyll and Hyde" situation transcends metaphor and becomes reality. When Booker at the end of the game kills COmstock, he is forced to take charge of the Hand of the Prophet and use the Songbird to destroy a Vox Populi attack - biologically, he is now the only Comstock around, and he is fulfilling Comstock's function. Immediately afterwards, Booker undoes Comstock's creation, but this does not stop the Jekyll from ever having existed. Booker is transferred back in time and actually merges with an earlier version of himself that is set on the path of becoming Comstock. The whole game has put our Jekyll and Hydes on a path towards an eventual merger into one body, in order for Jekyll to be "smothered in his crib" by a regretful Hyde.]]

* In the 2nd ''SummonNights'' for GBA, one of your Guardian Beasts is a trashtalking demon who claims to have been possessed by her angelic sweet side. Subverted in the matter that the demon is the leading personality, with the angel being the hidden "Hyde".

* ''WesternAnimation/CountDukula'' - episode "Doctor Goosewing and Mr. Duck". Von Goosewing invents a potion that reverses everyone's personality. He and Duckula become "wicious wampires", Igor becomes happy and loving and Nanny becomes a brainbox.

* Flippy from ''HappyTreeFriends''.

* ''WesternAnimation/{{Spider-Man The Animated Series}}'' - Norman Osborn and the Goblin; unlike most depictions, this version of Osborn was a decent guy (or at least trying to be one), while the Goblin was as homicidal as ever.

* The 1950 [[ClassicDisneyShorts Goofy cartoon]] "Motormania" features Goofy as the mild-mannered, friendly Mr. Walker. However, whenever Mr. Walker gets into his car, he becomes the ill-tempered, violent, and [[DrivesLikeCrazy reckless Mr. Wheeler.]]

* ''WesternAnimation/MaryShelleysFrankenhole'' has ''the'' Jekyll and Hyde, whose serum causes [[spoiler: JohnBelushi to turn into [[JamesBelushi Jim Belushi]]]]. Victor [[DeconstructedTrope also ridicules him]] for being his own monster.

* ''TheRobonicStooges'': "Dr. Jekyll And Hide Curly" has Dr. Jekyll's formula creating a Mr. Hyde on the ''back'' of his head only. He captures the Stooges and creates Hydes on the back of their heads that makes them imprison themselves.
* ''WesternAnimation/BatmanTheAnimatedSeries'' added another variation to this in Two-Face in the final season - [[spoiler: he'd established a THIRD personality called "The Judge", who targeted Gotham's costumed villains, including Two-Face himself, who would GoMadFromTheRevelation]].

** Specifically - * Looney Tunes - Friz Freleng seemed fond of this plot. He used it in 'Hyde and Hare'(with Bugs Bunny), 'Dr. Jerkyl's Hide'(with Sylvester), and 'Hyde and Go Tweet.(Sylvester and Tweety)' 'The Inspector' episode 'Sicque! Sicque! Sicque!' where Sgt. Deux-Deux drinks the classic potion and becomes a monster. In 'Pink Lightening' the same happens to The Pink Panther's car and 'Watch The Bidie' is pretty much a remake of 'Hyde and Go Tweet' with 'The Dogfather' characters instead.

* ''ThePerilsOfPenelopePitstop'': The Hooded Claw once rented a house from JekyllAndHyde as part of a plan to capture Penelope. After realizing there was no tea there, he improvised with some random ingredients. He planned to have the Bully Brothers capture Penelope while he distracted the Ant Hill Mob with the tea. However, the tea turned them into seven "Mr. Hyde" and they captured Penelope. To get their SentinentVehicle to cooperate, they gave it some of the "tea" and it also became a "Mr. Hyde".
* ''AtomicBetty'': Minimus' two personalities. The book was even mentioned in the episode where he got stuck on "Hyde" mode.
* 'Count Dukula' - episode 'Doctor Goosewing and Mr. Duck.' Von Goosewing invents a potion that reverses everyone's personality. He and Duckula become 'wicious wampires', Igor becomes happy and loving and Nanny becomes a brainbox.

* Harvey Dent, a.k.a 'Two-Face', of the ''Franchise/{{Batman}}'' mythos has this going on as well, with the split represented by Harvey's own 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 how [[WebVideo/TheSpoonyExperiment Spoony]] and [[spoiler: [[MadScientist Dr. Insano]]]] are portrayed in the ThatGuyWithTheGlasses anniversary special ''{{Kickassia}}''. (This is subject to NegativeContinuity.)
** NegativeContinuity indeed. [[spoiler: ''ToBoldlyFlee'' had retconned this into an anomaly caused by the PlotHole, in 'reality', Spoony and Insano are indeed two separate people.]]

* Odetta and Detta in ''TheDarkTower''.

** Specifically - * Looney Tunes - Friz Freleng seemed fond of this plot. He used it in 'Hyde and Hare'(with Bugs Bunny), 'Dr. Jerkyl's Hide'(with Sylvester), and 'Hyde and Go Tweet.(Sylvester and Tweety)'
* 'The Inspector' episode 'Sicque! Sicque! Sicque!' where Sgt. Deux-Deux drinks the classic potion and becomes a monster. In 'Pink Lightening' the same happens to The Pink Panther's car and 'Watch The Bidie' is pretty much a remake of 'Hyde and Go Tweet' with 'The Dogfather' characters instead.

* Looney Tunes - Friz Freleng seemed fond of this plot. He used it in 'Hyde and Hare'(with Bugs Bunny), 'Dr. Jerkyl's Hide'(with Sylvester), and 'Hyde and Go Tweet.(Sylvester and Tweety)'
* 'The Inspector' episode 'Sicque! Sicque! Sicque!' where Sgt. Deux-Deux drinks the classic potion and becomes a monster.

* 'The Inspector episode 'Sicque! Sicque! Sicque!' where Sgt. Deux-Deux drinks the classic potion and becomes a monster.