Character from Animaniacs by Steven Spielberg / WB
A giant chicken who wears paper-thin human disguises and somehow fools almost everyone — until one person doesn't buy it, and then everyone finds out at once.
The Chicken Boo segments are a study in collective delusion. He is clearly a giant chicken. He is wearing a hat. And yet, episode after episode, the world around him promotes him, admires him, and accepts him into positions of authority — doctor, soldier, romantic lead — while one lone voice insists he is a chicken and is dismissed as a crank. Chicken Boo doesn't speak. He clucks. He occasionally shows genuine competence in whatever role he has adopted, which makes the eventual reveal even better. When his disguise fails, the reaction is always the same: instantaneous, violent disillusionment, with the naysayer delivering 'I TOLD you that was a chicken!' directly to camera. He is a gag concept stretched to its philosophical limit — a test of how much a society will accept if the framing is confident enough.
A very large chicken. In disguise: whatever the plot requires — cowboy hat and bandana, business suit, lab coat — layered over an enormous chicken who does not actually look human at any angle. One person per segment sees through it immediately. Everyone else sees a normal human until the reveal.
Also known as: Chicken Boo, Boo