Carl Wheezer is Jimmy Neutron's nervous best friend in Jimmy Neutron: Boy Genius, the Nickelodeon series that ran in the 2000s. His nasal voice and easily panicked reactions made him a natural fit for short-form comedy, and clips of his screams and exclamations began circulating widely in TikTok and YouTube meme edits. Creators reuse the ahhh because it instantly signals overreaction without needing any context, and that instant recognition has kept the character popular long after the original show ended.