The Joker first appeared in Batman comics in 1940 as the hero's clown-like arch enemy, and his laugh became a signature across animated series, films and games. Different actors have shaped it into a high, taunting cackle that signals danger disguised as a joke. Online, short clips of that laugh were cut from trailers, cartoons and gameplay and reused as a reaction sound on forums and video edits. It remains popular because a few seconds instantly communicate smug, unhinged delight without needing any setup or dialogue from the scene itself.