“What’s up, Doc?” is Bugs Bunny’s best-known catchphrase from the Looney Tunes and Merrie Melodies cartoons produced by Warner Bros. The line is strongly associated with his 1940 breakout short A Wild Hare, which helped define the character’s cool, sarcastic persona. Over time, the quote became one of the most recognizable cartoon lines in popular culture. Online, creators still use it because the delivery is instantly understood and can turn a tense, silly, or ironic moment into a quick visual joke.