The line comes from The Incredible Hulk, where Bruce Banner warns others before transforming into the Hulk, and the phrase 'you wouldn't like me when I'm angry' became one of the character's most recognisable warnings. It spread beyond comics and television into films, games and internet culture, where the calm delivery made it easy to reuse as a joke. On soundboards and social video it is now used as a mock threat before an outburst, a fail or a revenge moment, keeping the reference alive for viewers who may never have seen the original show.