This sound is associated with Pennywise from the 2017 film IT, based on Stephen King's novel. The character's laugh became a popular audio snippet in horror memes, creepy edits, and villain-themed compilations after the film's release. Online, people use it as a quick shorthand for menace, eerie amusement, or a twisted reveal. It remains popular because the laugh is instantly recognizable, short enough for punchy editing, and effective even when dropped into otherwise normal or comedic footage.