The phrase comes from 'Who's That Pokemon?', a recurring segment in the Pokemon animated series that began in the late 1990s during the original run of the show. Each segment showed a Pokemon in silhouette during a commercial break and revealed it afterward, turning identification into a game for young viewers. The clip spread online as a meme sound for guessing games and surprise reveals, helped by nostalgia for the series and by translations in other languages, including Portuguese versions shared on soundboards.