“Poyo” is widely recognized as Kirby’s trademark vocalization from Nintendo’s Kirby series, first associated with the character in the early 1990s. The sound became especially familiar through Kirby games and animated appearances, where it helped define his cute, simple personality. Online, creators use it as a quick reaction sound for adorable, innocent or unexpectedly funny moments. Its staying power comes from how instantly recognizable it is to Nintendo fans and how well one tiny word can sell a whole mood.