The Joker, Batman's most infamous adversary, is defined as much by his laugh as by his crimes, and clips of that cackle have circulated online for years as a shorthand for chaos and twisted humour. Fans and editors lift the laugh from films, games and animated appearances to punctuate betrayals, reveals and ironic victories, and it has become a staple of villain edits, reaction videos and Halloween content. Its staying power comes from instant recognition: one burst of laughter signals that something has gone deliciously wrong.