Nyeh heh heh is the signature laugh of Papyrus, the enthusiastic skeleton from Toby Fox's Undertale, released in 2015. Papyrus uses the laugh when he is trying to sound like a fearsome villain, even though he is warm, earnest and famously bad at being scary, which is why fans adopted it as a joke. Clips of the laugh spread through Undertale playthroughs, animations and short-form edits, where it became shorthand for misplaced confidence. It remains popular because it is instantly recognisable, easy to place over a reveal, and funny without needing any context from the game.