The laugh comes from Heath Ledger's portrayal of the Joker in Christopher Nolan's The Dark Knight, released in 2008. Ledger's performance, including the character's distinctive, unhinged laugh, became one of the most discussed aspects of the film and helped redefine the comic-book villain on screen. As clips circulated on YouTube, TikTok and soundboard sites, the laugh was detached from its scenes and reused as shorthand for chaos, scheming and dark humour. It endures because the performance remains instantly recognisable, even to viewers who have not seen the full film.