History Main / HydePlaysJekyll

* ''Anime/{{Bakugan}}: Hal-G, evil personality of Michael Gehabich after he was corrupted by the negative energy of the Silent Core, pretends that Michael has finally regained control and desperately needs the positive energy of the Infinity Core within Wavern to stop Hal-G from taking back control to trick Alice into leading him to Wavern.

* Mal pretends to be Mike while under the influence of the Blue Harvest Moon in ''WesternAnimation/TotalDrama All Stars''. He continues to do this while he's in complete control.

* In ''No Turning Back'' story arc of ''[[ComicBook/SpiderMan The Amazing Spider-Man]]'' (issues 688 - 691) heroes inject the Lizard with a serum that seemingly turns Connors back into human. Unbeknownst to them, they managed to restore his physical form only and Lizard's personality is still in control -- and more than a little furious that he was turned into a [[PunyEarthlings meager human]]. Naturally, he hides that fact and poses as Connors for some time (cutting off his arm as it keeps regrowing) while secretly working on creating a formula which will turn him back into Lizard. However, [[HumanityIsInfectious he starts to enjoy his new life as a human]] and hesitates when he is about to finally inject himself. He is given no choice, however, when his cover is eventually blown (he cut off the wrong arm by mistake and the nature of his experiments is finally revealed) and he is forced to defend himself from Spider-Man. [[spoiler:This leads to an inverted case of Jekyll Playing Hyde when turning into the Lizard restores ''Curt's'' mind. Curt pretends to be the Lizard anyway because he feel so guilty about everything he did as the Lizard (especially ''killing and eating his own son Billy'') that he ''wants'' to be locked up like an animal forever.]]

** One race, the Tollan, actually defied this trope with a device that allowed the host and Goa'uld to alternate control of the body, and glowed blue or orange to let everyone else know who was talking.

* In Eirika's route of ''VideoGame/FireEmblemTheSacredStones'', the Demon King, possessing Lyon's body, pretends to be Lyon FightingFromTheInside to trick Eirika into giving him the Renais' Sacred Stone. The situation is reversed of Ephriam's route, where Lyon is a legitimate WellIntentionedExtremist and pretends to be possessed by the Demon King to manipulate Ephriam.

* ''FanFic/RosarioVampireBrightestDarkness Act II'': After seeing Kokoa's newfound [[SuperMode overcharge]] in action, as well as realizing Kokoa's newfound feelings for Tsukune, Tsukune's [[SuperPoweredEvilSide inner ghoul]] manages to seize control of Tsukune without Tsukune's knowledge and uses said feelings to manipulate Kokoa into using said overcharge to give it enough power to become a full-fledged ghoul and hijack Tsukune's body completely. In Act III, it's largely because of this that, even with the [[RestrainingBolt Holy Lock]] keeping the ghoul sealed away, Dark is initially so dead-set against trusting Tsukune to keep the ghoul in check again since he already failed to do so once.

* At the end of ''Videogame/{{Mardek}}: Chapter 3'', when Rohoph becomes paranoid and decides that friends are a liability, he starts by brutally rejecting one of [[SpoonyBard Elwyn's]] romantic attempts while she thought she was talking to Mardek. Of course, it only worked because his [[TwentyFourHourArmor helmet]] concealed Rohoph's GlowingEyesOfDoom.

** ''Series/StarTrekVoyager'': In the two-parter "Equinox", the EMH from the USS ''Equinox'', whose ethical subroutines were deleted, forcibly trades places with the Doctor from ''Voyager''. Posing as his ''Voyager'' counterpart, he helps free his ship's officers after they're arrested and later secretly gives information about ''Voyager'' to them. While aboard the ''Equinox'', the Doctor has his own subroutines suspended by Capt. Ransom and forced to operate on Seven. After he's brought back to normal on ''Voyager'', the Doctor lampshades this trope, saying "It's quite disconcerting to know that all someone has to do is flick a switch to turn me into Mister Hyde.".

** ''Series/StarTrekVoyager'': In the two-parter "Equinox", the EMH from the USS ''Equinox'', whose ethical subroutines were deleted, forcibly trades places with the Doctor from ''Voyager''. Posing as his ''Voyager'' counterpart, he helps free his ship's officers after they're arrested and later secretly gives information about ''Voyager'' to them.

** ''Series/StarTrekVoyager'': In the two-parter "Equinox", the USS ''Equinox'''s EMH, whose ethical subroutines were deleted, forcibly trades places with ''Voyager'''s Doctor. Posing as his ''Voyager'' counterpart, he helps free his ship's officers after they're arrested and later secretly gives information about ''Voyager'' to them.

* Used briefly in ''Series/StarTrekDeepSpaceNine,'' when Sisko is the temporary body for Dax's murderous previous host Joran.

* ''Series/StarTrekTheNextGeneration'': Inverted in "I, Borg". When Picard first meets with Hugh, the latter identifies him as Locutus (despite the very obvious fact that Picard is no longer Borg). Picard plays along with this, claiming he is there to facilitate humanity's assimilation, and ordering Hugh to assist in assimilating the Enterprise. He's utterly thrown when Hugh insists [[WhamLine "I will not!"]].

* In ''LightNovel/IzureShinwaNoRagnarok'', Ruirui Shishigane is possessed by Freyja, who pretends not to be possessed in order to set a trap for the protagonist.

* Used in ''Series/StarTrekTheNextGeneration''. When Picard first meets Hugh, a Borg drone that has developed individuality during his time on board the Enterprise, he is mistaken by Hugh to still be Locutus of Borg, a mistake Picard goes along with to try to prove that Hugh is still nothing more than a Borg drone.

* Played with somewhat in ''Film/PrimalFear''. The "Jekyll" of the story is Aaron, a sweet natured NiceGuy who, as it turns out, was severely abused including sexually as a kid. The "Hyde" is Roy, a ruthless, violent manipulator who killed the PedophilePriest who abused Aaron as a youngster. Every now and then when Aaron gets sufficiently stressed he starts MissingTime and Roy takes over, and afterward Aaron can't remember what Roy did. At the very end of the movie [[spoiler:after his defense attorney has gotten Aaron an insanity plea]], Aaron makes a reference to something that Roy did and we get this exchange:

* In the ''WesternAnimation/Ben10Omniverse'' episode "Max's Monster": [[spoiler:"Kid, there hasn't been a Phil in this body for years."]]

* From ''Film/PrimalFear'':

* ''VideoGame/FateGrandOrder'': Being the TropeNamer himself, Hyde does this from time to time, deliberately making it difficult for Fujimaru to tell whether they're talking to the kindly NervousWreck Henry Jekyll, or the psychotic KnifeNut Edward Hyde. It doesn't help that both personalities can influence each other, leading to Jekyll acting off at the slightest trigger, or Hyde abruptly calming down when he runs out of steam.