Easy Impersonation

Oh no! The Cape's reputation is in jeopardy! All of a sudden, he's being accused of crimes he's never committed, and the police are after him! He knows that he never committed such vile deeds. Surely this must be the work of an evil Doppelganger!

After trying to clear his name, the hero finally finds his impersonator, who... doesn't really look that much like him. For starters, his insignia looks like it was made of cardboard, his costume is black, and, of course, he has that goatee. And don't even get started on how he renders the hero's catch phrase.

In a nutshell, this is when the hero's Evil Twin or other evil lookalike doesn't look that much like their duplicate at all. It seems that the only reason anyone could possibly have mistaken one for the other is because the entire populace had just been handed the Idiot Ball. In extreme cases, the doppelganger never actually intended to fool anyone: they just looked vaguely similar, so people mistook one for the other anyway.

This trope is often used for comedy. When played seriously, this can be a case of Viewers Are Morons: While subtle differences in appearance are both expected and useful for the viewer, it can be insulting when the similarities between them are few and far between. If you have to ask yourself, "Wait, how could you have possibly mistaken one for the other?" then it's probably this trope.

Compare Paper Thin Disguise. See also Costume Copycat.

Anime and Manga

 * In one episode of Di Gi Charat, Dejiko is accused of various misdeeds by the other members of the cast. Though she insists she's innocent, no one believes her. She attempts to bribe the other characters into forgiving her with some Dejiko Candy, which happens to draw out her imitator, which is simply a blob with a Dejiko hat.
 * The 2003 anime version of Fullmetal Alchemist has the Other Brothers Elric. Though they’re not evil, they do cause trouble for Ed and Al. And vice versa, actually. For example, the fake Elrics get arrested when a warrant goes out for the real one. Now, the fake Elrics do look somewhat like the real ones did before they lost or maimed their bodies, but no one who saw them since would be fooled. Ed has Artificial Limbs, and Al is Animated Armor.
 * Part of this is just that nobody who hasn't seen them before seems to know what they look like, and just assumes it's them based on the height difference and blonde hair. It's part of the same gag for why people mistake Al for Ed.
 * After One Piece's Time Skip, the Straw Hats return to Saobondy to learn that a bunch of imitators are trying to use their reputation to bluff and bully other people. The fakes' disguises are poor, to say the least (For example, Fake Luffy and Sogeking are overweight and bearded, and Fake Chopper is a fox), but everyone assumes the 'Straw Hats' appearences must have changed the in the two years they were last seen. The real Straw Hats don't seem to care either way, (Except for when the dumber crewmates fall for the ploy), and are willing to let their impersonators suffer the inevitable consequences of pretending to be world-class criminals.

Comicbooks

 * The current Venom (as in, the one in the Thunderbolts) is still being mistaken for Spider-Man, leading Spider-Man to get a bad reputation for murdering people. Strangely, the new "Spider-Man" is wearing the black suit, while the other one is wearing the ol' red and blue.
 * That and Venom has a big toothy mouth and a giant tongue. And is about twice Spidey's size.

Films -- Live-Action

 * Played to some extent in The Dark Knight. Batman has to deal with a number of impostors who, upon close examination, barely resemble him (one's overweight). Leads to the "hockey pads" line. Of course, since Batman is essentially an American Ninja, few people ever get a closer look at him. It's also worth noting that the Scarecrow--the one guy in this scene who had fought Batman before--recognized that these Batmen were impostors, mostly because they used guns.
 * In the fourth Pirates of the Caribbean movie, the pirate who has been impersonating Captain Jack Sparrow (and very convincingly, at that) turns out to be a girl.

Live-Action TV

 * In Buffy the Vampire Slayer, when the Scoobies mistake the Buffybot for Buffy she gets very angry that they can not tell the difference. To be fair, the 'Bot does really look like her....until it opens its mouth, of course.
 * In a Superdude skit on All That, Superdude (Keenan Thompson) was baffled that an impostor (Amanda Bynes) had all the people fooled. He even lampshaded the fact that a small white girl looks nothing like a larger black guy and that she didn't even have superpowers.
 * Starsky and Hutch: One episode revolves around an attempt to discredit Starsky and Hutch by having impersonators commit crimes. While the impostors bear a fair general resemblance, it's nowhere near good enough to justify having a woman who knows the real cops on sight get a good look at both pairs, five minutes apart, and be unable to tell the difference.
 * During the Mystery Science Theater 3000 episode "Hobgoblins", the Satellite of Love crew creates cardboard cut-outs of themselves, a generic tape recording. This fools Pearl and Bobo. Brain Guy can see through the disguise, but has trouble convincing the others until Mike's cut-out falls down and he enters the frame to right it.

Videogames
"RED Demoman: *Bzzt* "I-will-kill-the-Soldier." *Bzzt* *Bzzt* "He-is-a-bad-friend." *Bzzt*
 * In Sonic Adventure 2, Sonic is imprisoned for crimes committed by the recently un-Sealed Badass in A Can, Shadow the Hedgehog. Where this trope comes into play is the fact that Shadow has a different coloration, different spike patterns, and otherwise only has the slightest of similarities. At one point, a reporter even puts up footage of Shadow and claims him to be Sonic. This also falls under the "Not even trying to fool anyone" clause; when they finally meet, each claims that the other is their fake.
 * And of course, the scene where Amy, Sonic's stalker, mistakes Shadow for him, despite her approaching while he's having a non-hostile conversation with Dr. Robotnik. She eventually realises her mistake after she hugs Shadow.
 * Amy has also mistaken Silver the Hedgehog for Sonic (again, different spike patterns and color) in Sonic the Hedgehog 2006, and in Sonic Unleashed she glomped Sonic himself without noticing that he had been transformed into a hedgehog-werewolf. Theory has it that Amy is near-sighted.
 * This also happens in the OVA. Tails describes Metal as "a robot that looks exactly like Sonic!", and Amy is fooled enough to go up and hug it. Metal is silver, shiny, and has a rocket engine in its back.
 * Furio Tigre impersonates Phoenix Wright at one point during Trials and Tribulations, purely because they have similar hair. Note that Tigre is buff, has a completely different disposition, and is orange. Oh, and his attorney's badge is made of cardboard.
 * At least with the Phoenix Wright example, the writers had the decency to have Phoenix lampshade the sheer stupidity required on the part of everyone involved in the case to not recognise that it wasn't him.
 * In the opening act of Super Mario Sunshine, Mario is sent to Kangaroo Court and imprisoned based on his resemblance to a rough police sketch of the perpetrator: Shadow Mario.
 * Made especially stupid when even a casual observer would have noticed that Mario had only been in the country for a matter of minutes when he was arrested, making it impossible for him to have committed the crimes that had been happening over the past week.
 * Played hilariously straight, along with a Lampshade Hanging, in this comic accompanying the WAR! Update in Team Fortress 2.

BLU Soldier: "Ahhhh, but damnit - it doesn't matter what he said in that weird robot voice I've never heard him talk in before.""


 * Not to mention the in-game disguise ability of the Spy class. While the spy looks like the intended class to everyone on the opposite team, everyone on the Spy's team sees them as they are, wearing a paper mask of the intended target.

Western Animation

 * Played for laughs in Spongebob SquarePants in that the duplicate of Mr. Krabs made by Plankton was horrendously fake. However, Spongebob still couldn't tell the difference, despite the fake talking in a Creepy Monotone, having a metal body with a Paper Thin Disguise, and shooting lasers.
 * In the 1980s Teenage Mutant Ninja Turtles cartoon, Shredder sends mutant frogs on a crime spree, and the Turtles get blamed. When the two groups finally confront each other, Donatello lampshades this by saying "I am so insulted. How could they mistake these things for turtles?"
 * In an earlier episode Shredder trains a group of karate students and sends them on a crime spree wearing bad turtle costumes and calling themselves "The Crooked Ninja Turtle Gang". Naturally Channel 6 News eats it right up, since it's boss hates the turtles anyway.
 * One episode of The Powerpuff Girls had a trio of burglars get into Powerpuff Girls Halloween costumes and claim to be the Powerpuff Girls. Despite their being about three times taller than the girls, with hairier legs, fingers and masculine voices, everyone except Ms. Bellum actually believed that they were the Powerpuff Girls, and the girls got in trouble for everything the crooks did.
 * Underdog was once jailed for crimes committed by Tap-Tap the Chiseler. Despite being a cigar smoker, Tap-Tap fooled everyone with his Underdog costume.
 * One episode of Chip 'n Dale Rescue Rangers had Dale picking up a meteorite fragment that allowed him to turn into a Rubber Man; sick and tired of being The Load, he adopts the Secret Identity of "Rubber Bando" and leaves the rest of the Rangers feeling inadequate. Unfortunately, a bigger chunk of the meteorite fell into the hands of a sleazy travel agent named Seymour, who began abusing its power to steal entire monuments. Naturally, his shenanigans were blamed on Dale, even though Seymour was quite obviously several times bigger.
 * Another episode involved Fat Cat's gang framing movie star Flash the Wonder Dog with the trademark bark, Hilarity Ensues.
 * In Gummi Bears, while not abused as such, Cubbi's alter ego of the Crimson Avenger ends up wrapped in so much legend that no one bats an eye when someone who is most obviously not the diminutive bear shows up in costume claiming to be the Zorro-esque (or perhaps more appropriately, Red Whirlwind-esque) hero.
 * In an episode of Sushi Pack, four members of the Pack are framed for robbing a bus, and are sentenced to house arrest, despite surveillance video showing the real culprits are simply the members of The Legion of Lowtide painted to be the right colors.
 * In the Batman the Brave And The Bold episode, "Game Over for Owlman!", Batman is framed for crimes committed by his evil counterpart from a mirror universe. Said double is wearing a costume with pointier ears and a darker color scheme. The only person who figures out it's an impostor is not one of Batman's superhero allies, but the Joker.
 * To be fair in this case, the costume in question was based on the one Batman wore in his first appearance and it was later revealed in the episode, "The Golden Age of Justice!", that Batman did wear that costume when he was starting out.
 * Deconstructed in The Spectacular Spider-Man. When Chameleon impersonates Spider-Man, his impersonation is bad enough that the audience, who constantly sees the wall crawler in action, clearly know it's a fake, but to people in the actual world, most of whom have never seen anything more than a photograph, he's close enough to convince them. Detective Stacey is familiar enough with the web head to immediately know he's a fake. It's later played ridiculously straight when Venom tries to frame Spider-Man, and nobody (except Stacey) notices that he's two feet taller, built like a brick, fights completely differently, and has razor sharp teeth and a salivating tongue.
 * A hilarious example in The Tick, when criminals stole Tick and Arthur's arms and went on a crime spree. (The only part of them that even slightly resembled Tick and Arthur were... their arms. Despite that, everybody was fooled.)
 * The Avengers: Earth's Mightiest Heroes has a Skrull impersonating Captain America for the first few episodes of the second season. The Skrull wears Ultimate Captain America's suit, even though the real Cap has the costume from the main Marvel Universe. He did wear the normal costume when capturing Cap, and viewers don't know exactly how much time passed until he changed his clothes. This might justify the fact the Avengers didn't question the outfit change right when season 2 began.