The sound comes from Jim Carrey's portrayal of Ace Ventura, the eccentric pet detective introduced in the 1994 film Ace Ventura: Pet Detective and carried into its 1995 sequel. Carrey's broad physical comedy and elastic vocal delivery made many of the character's lines easy to lift out of context, and this single-word reaction was no exception. Shared through soundboards and short-form video, it became a quick shorthand for disbelief. It remains popular because one sarcastic word can punctuate a joke without needing any setup or explanation from the original film.