Scooby-Doo first appeared in 1969 in the Hanna-Barbera cartoon Scooby-Doo, Where Are You!, where the cowardly Great Dane became famous for his nervous laugh, his love of Scooby Snacks, and his habit of fleeing from monsters. The rehehehe laugh, originally voiced by Don Messick, became one of the character's signature sounds and has been reused across decades of cartoons, films, and parodies. Online, short clips of the laugh spread through meme edits, reaction videos, and soundboards, where it still signals goofy fear and comic relief.