Carl Wheezer is the anxious best friend of Jimmy Neutron in the Nickelodeon animated series Jimmy Neutron: Boy Genius, which began as a 2001 film before becoming a television series. Voiced by Rob Paulsen, Carl is known for his nervous manner, love of llamas and tendency to panic over everyday dangers, so a tiny startled ahh fits his character perfectly. The clip has circulated on soundboards and in short-form edits, where cartoon reaction sounds are reused to exaggerate surprise, and it remains popular because it is short, instantly recognisable and easy to drop into almost any moment.