Bluffing the Imposter in Western Animation.
- The Beatles episode "No Reply" had the boys on vacation in Hawaii where there are suddenly two Pauls. One of them is a criminal master of disguise named Anyface, and nobody can tell who is who until a bevy of fangirls show up. The impostor does not run.
- Butch Cassidy and the Sundance Kids: In "Double Trouble" the kids use rock trivia to find out which Prince Taki is the real one. Given the prince is a big rock fan and the imposter has no clue. For example, Wally asks him who drummer of The Beatles is and turns it into a trick multiple choice question. The imposter screws it up so badly, his answer is "George Harris' son."
- Family Guy:
- Spoofed in the episode "German Guy": when Chris discovers that his new elderly friend Franz is a former SS officer, Franz holds Peter at gunpoint, but Peter knocks his gun out of his hand, allowing Chris to get it. Chris suddenly thinks that Franz is Peter's Evil Twin and asks them what's his birthday. Franz answers correctly and Chris shoots Peter and hugs Franz, who takes back the gun. Peter rightfully calls Chris out for his incompetence, but Chris argues that he should've learned his birthday.
- The episode "The Hand That Rocks the Wheelchair" has Stewie trying to undo his in-universe Villain Decay, but instead accidentally makes himself an Evil Twin. When the two fight at the episode's climax, they remove each other's clothes and entrust Brian to shoot the right one. Brian remembers that the real Stewie is amused by the sight of his own feet and shoots the one who doesn't laugh at them, but the episode ends with a parody of the ending of "Thriller" that implies he killed the original (for that episode).
- Hilariously overblown in Fantastic Four: World's Greatest Heroes "My Neighbor Was A Skrull" when shapeshifting aliens are posing as every single one of the heroes' neighbors and acquaintances. Reed Richards starts asking questions like "Do you remember when we first met? Was it... five hundred years ago? On the moon? Remember, you flew up there in your bathtub?" and "I always loved your wings, Mrs. Smith. They're so white and fluffy. Would you show them to me, please?"
- In the Futurama special Bender's Game, Larry, Walt, and Ignur turn up at Planet Express dressed as owl exterminators, in an attempt to steal the Anti-Crystal. Fry falls for it, but Farnsworth sees through them immediately and presents them with an owl. They hilariously fail to exterminate it and their cover is blown.
- In the G.I. Joe: A Real American Hero episode "Cobra's Creatures", the Joes attempt to stop Dr. Lucifer by having Scarlett impersonate Dr. Atilla, a scientist he has feelings for. Dr. Lucifer suspects that something is amiss and asks the disguised Scarlett if she remembers when he proposed to her. Scarlett answers that she does remember, which confirms Dr. Lucifer's suspicions that she's an imposter, revealing that he never proposed to Dr. Atilla.
- Harley Quinn: When Harley decides to rob Maxi Zeus, she has Clayface act as a distraction. As Clayface in this version is a ridiculously over-dramatic would-be actor, he makes up an absurdly elaborate cover story about being Maxi's long-lost son from a one-night stand that Maxi had decades ago. Maxi gets suspicious and asks how it is that his "son" didn't inherit his mother's bright blue eyes, at which point Clayface changes his eye color (which had matched Maxi's) to bright blue. Maxi then proceeds to bluff him with a ridiculous list of various traits that Clayface "should" have inherited, with Clayface changing to add each one. By the time Maxi calls the thing off, Clayface has turned himself into a lisping, hunchbacked, grotesquely deformed freak.
- The Miraculous Ladybug episode "Copycat" sees Chat Noir impersonated and defeated by the Akuma of the Week, but he suggests that Ladybug ask the other one, who's got him pinned, about their love. It works like a charm.The Real Chat Noir: If you don't believe I'm the real Chat Noir, ask him about our love for each other!
Ladybug: Uhh...
The Real Chat Noir: Have I ever lied to you, Bugaboo? *winks* - In one episode of Ninjago, Lord Garmadon creates evil clones of the ninja team. When Sensei Wu meets the impostors, he becomes suspicious of them and remarks that Lloyd must be having fun at the amusement park they left him at. The fake ninja go along with the amusement park story, unaware that Lloyd is actually at his old boarding school with the real ninja, proving to Wu that they're fakes.
- In the Hub's Pound Puppies, Squirt trades places with pampered house pet Cuddlesworth in "The Prince and the Pupper", and meets Cuddlesworth's fellow pet, a Persian cat named Madame Pickypuss. Pickypuss manages to confirm that Squirt is an impostor when he accepts a treat that she knows her friend Cuddlesworth hates.
- In The Real Ghostbusters, Egon bluffed a Janine imposter by referring to his mother as his Aunt Helga. The real Janine would recognize Egon's mother because they've met before.
- In the Regular Show episode "Temp Check", a temp that Rigby hires turns out to be a shapeshifter that gradually changes until it's impossible to distinguish between the two of them. The attempt to get the impostor to expose himself by asking questions fails, so Mordecai offers the winner of the challenge a hug. "Rigby" takes it, which outs him as the impostor (since, earlier in the episode, it's shown that Mordecai and Rigby would never hug one another.)
- In the Rick and Morty episode "Air Force Wong", the entire state of Virginia gets taken over by Rick's ex Unity, and his therapist Dr. Wong gets caught up in the mess. After getting separated and running into Wong, who claims he should try talking to Unity, Rick refers to her as a nutritionist. When Unity goes along with the act, Rick immediately sprays Wong with the anti-Unity gas to free her.
- Sonic the Hedgehog (SatAM) Tails warns Sonic that the Sally at present was an imposter, but he doesn't believe him. Not at first, anyway. Sonic later bluffed Sally with a long and rather complicated handshake that they tended to use. However, he changed the last part from a thumbs-up to a thumbs-down. When Sally followed along and didn't correct him, Sonic realized Tails was right and revealed that she was a robot while the real Sally was captured.
- In the Transformers: Prime episode "Con Job", the Decepticons employ a superlative shapeshifter Transformer called Makeshift to impersonate Bulkhead's Wrecker buddy Wheeljack, who then infiltrates the Autobot base. Bulkhead suspects something's wrong all through the episode, and finally forces 'Wheeljack' to tell the story of a famous battle. Makeshift talks about a fight alongside Bulkhead and the other Wreckers, and at first it looks like he gets it right, but...Bulkhead: Yeah, that's exactly how it happened, except for one little thing: I wasn't there. I'd already left the Wreckers to join up with Optimus, but you wouldn't know that if all you did was access Wheeljack's public service record.
- In Thunderbirds Are Go, the main characters unmask an AI pretending to be one of their siblings by asking if he misses their Lethal Chef grandmother's cookies. When "he" says yes, they immediately know they're not actually talking to him.
- In T.U.F.F. Puppy, The Chameleon got into a tussle with Dudley, while disguised as Dudley, Kitty was able to tell who was the real Dudley by getting one of them to spell Dudley's name, the Chameleon got it right and she blasted him. The real Dudley can't spell his own name, let alone write it down.
- In the Wild West COW Boys Of Moo Mesa episode "Stolen on the River", Cowlorado Kid infiltrates a luxury riverboat cruise, in an attempt to nab notorious outlaw and gambler Five Card Cud. Five Card questions his cover story: if Kid is such an accomplished high roller, surely he knows Snake Eye Smithson? Kid claims he won a bundle off Smithson just last week, confirming Five Card's suspicions. After all, Smithson has been dead for over 10 years since Five Card killed him himself.
