History SpotTheImposter / WesternAnimation

** When Bishop comes across Mystique disguised as Gambit and Gambit himself, Mystique tries to convince him that she's the real Gambit, but Bishop (who hates Gambit anyway) simply plans on blasting them both without prompting. He's stopped by Rogue. Granted there was the simple way of only the real Gambit being able to use his powers anyway, but again, Bishop didn't like him enough to try.

* ''WesternAnimation/TheSimpsons'':
** Subverted in "[[Recap/TheSimpsonsS14E1TreehouseOfHorrorXIII Treehouse of Horror XIII]]"; when an army of marauding Homer-clones attack, Marge stops them by leading them into a canyon. She returns to Homer, but finds out the one that survived was actually a clone; however, he starts giving her a backrub, and she decides she doesn't mind too much.
** In a non-THOH ep., Homer becomes a local Krusty "helper" (i.e. dons the makeup and costume so as to look identical to the original for local publicity), but the original Krusty is in trouble with [[TheMafia the Mob]]. Both end up cornered at gunpoint in an AbandonedWarehouse, where the villains are initially flummoxed as to which one to shoot (which partly lampshades the show's [[OnlySixFaces limited animation character styles]] as both Homer and Krusty share the exact same basic frame, as well as both being voiced by Creator/DanCastellaneta, which [[WordOfGod Groening actually intended]] so as to create a dynamic where Bart hated Homer but worshiped a man who looked just like him in the original shorts, and one of the early shorts story ideas was the revelation that Homer was Krusty), until Homer blows their cover by addressing Krusty by name. This being comedy, they survive anyway. Despite the limited animation character style, it actually was quite easy to tell the two apart - Krusty has a tuft of green hair on the top of his head, Homer two single hairs combed over it.

** Parodied in the episode "German Guy", where Chris befriends an elderly puppeteer, Franz Gutentag [[AllGermansAreNazis but discovers that he used to be a Nazi.]] When Franz finds out, he takes Chris and Peter hostage; Peter knocks the gun out of his hand, and Chris grabs it, but suddenly he's confused which one to shoot, even though, as Peter points out, they look nothing alike. Chris asks when his birthday is; Peter doesn't know, but Franz does, so Chris ends up shooting Peter in the shoulder.

* ''WesternAnimation/SpongeBobSquarePants'': In the episode "Imitation Krabs", [[IdiotHero [=SpongeBob=]]] can't distinguish between Mr. Krabs and Plankton's robotic replica of Krabs -- even though one is [[PaperThinDisguise clearly a robot]], complete with {{Robospeak}} (though [=SpongeBob=] did get weirded out by the robot's "metal pants"). [=SpongeBob=] gives the two Krabs a series of questions he thinks only the real Mr. Krabs would know the answer to. However, the first two are generic questions that anyone who's been to the Krusty Krab can answer, and the third is so complicated that even the real Krabs can't answer it.

->'''Dewey:''' Uncle Scrooge, stop the bad guy!\\

** In "A Tale of Two Snottys", Eugene (A.K.A. Snotty Boy) gets amnesia and the animals send Pig dressed in his clothes to the Beadys' house until they can restore Eugene's memory. When Eugene does get his memory back, Mrs. Beady is unable to tell them apart, even though they not only look nothing like each other, but are also dressed in different clothes and have different personalities. However, the third difference is exposed when Pig saves Mr. Beady from a fallen ship in a bottle, as Mrs. Beady knows the real Eugene wouldn't risk his life to save her husband.

** The TooDumbToLive citizens of Townsville take three hardened criminals poorly disguised as the actual heroines in "Powerpuff Bluff". The real Powerpuffs get locked in jail.

::: Even worse, later when the girls and imposters confront each other even THEY can't tell the difference between the reals and fakes, resulting in them each hitting their own side, to which Blossom suggests they fight their counterparts so nobody got confused.

* On ''WesternAnimation/RegularShow'' a shapeshifting otter tries to take Rigby's place and the others can't tell them apart. Mordecai points at one of the Rigbys as the real one and asks for a hug. He does... which is how Mordecai knows he's the imposter, because the real Rigby hates to hug.

* In an ''WesternAnimation/SouthPark'', Cartman's EvilDoppelganger from the MirrorUniverse shows up. Except, since the regular Cartman is evil already, the "Evil" Cartman is actually good. So much so that, when it comes time to send him back, [[PreferableImpersonator everyone decides they'd rather keep him and send the regular Cartman to the other universe instead]]. There's a scuffle in which the two get mixed up, and one of the Cartmans tells the group to shoot both of them, as its the only way to be sure. Assuming that one must be the Evil (Good) Cartman, they shoot the other one, only for the remaining Cartman to suddenly start gloating that he's actually the regular one, [[GenreSavvy and he knew they'd fall for the old "shoot us both" trick]].

* ''WesternAnimation/SpongeBobSquarePants'':
** Averted in the episode "I'm With Stupid", when the visiting starfish couple Marty and Janet call each other by name, Patrick immediately realizes they are not his parents. His actual parents are named Herb and Margie.
** In the episode "Imitation Krabs", [=SpongeBob=] can't distinguish between Mr. Krabs and Plankton's robotic replica of Krabs -- even though one is [[PaperThinDisguise clearly a robot]], complete with {{Robospeak}} (though [=SpongeBob=] did get weirded out by the robot's "metal pants"). [=SpongeBob=] gives the two Krabs a series of questions he thinks only the real Mr. Krabs would know the answer to. However, the first two are generic questions that anyone who's been to the Krusty Krab can answer, and the third is so complicated that even the real Krabs can't answer it.
* In the ''WesternAnimation/StaticShock'' episode "Toys in the Hood" (a cross-over with Superman), the Toyman creates a synthetic copy of Static's girlfriend Daisy, forcing Superman and Static to figure out which is which. The copy is such a perfect match that even with his x-ray vision Superman cannot tell the real Daisy from the fake one. Static solves the problem by making the electric aura that all humans have visible; the Daisy without an aura is the fake one.

* ''WesternAnimation/TheLifeAndTimesOfJuniperLee'': Ray Ray has to identify the real Juniper. One failed attempt consists on asking both Junes to tell her middle name. Both knew it is "Kim". Ray Ray eventually manages to tell who the real is the same way Jade did with Jackie in an above example. To her dismay, he is helped by a zit she tried to rid herself of earlier.

* In the ''Franchise/TheLegendOfZelda'' [[WesternAnimation/TheLegendOfZelda1989 cartoon]] episode "Doppelganger", Ganon creates an identical copy of Princess Zelda to infiltrate the royal palace and steal the Triforce of Wisdom. Near the end, when he's finally aware that there are two Zeldas, and as the real Zelda tackles her clone to try to take back the Triforce before she could give it to Ganon, they are both soaked in muddy water, turning their clothes brown to the point it's impossible to tell them apart. Link is able to spot the fake by asking them each for a kiss. The false Zelda is perfectly willing to give him one; the real Zelda, by contrast, refuses. "''That's'' my Zelda!"

* In one episode of ''[[WesternAnimation/TheLegendOfZelda1989 The Legend of Zelda]]'' cartoon, Ganon creates an identical copy of Princess Zelda to infiltrate the royal palace and steal the Triforce of Wisdom. Near the end, when he's finally aware that there are two Zeldas, Link is able to spot the fake by asking them each for a kiss. The false Zelda is perfectly willing to give him one; the real Zelda, by contrast, refuses. "''That's'' my Zelda!"

::: Even worse, later when the girls and imposters confront each other even THEY can't tell the difference between the reals and fakes, resulting in them each hitting their own side.