Undertale Yellow is a fan-made prequel to the indie role-playing game Undertale, made by fans rather than the original developers, and it brings back Flowey, the smiling flower who first greeted players in Undertale. In this fan game, Flowey again mixes helpful advice with something darker underneath, which is why clips of his voice travel so well outside the game itself. Shared in edits, reaction videos and short-form posts, the sound has become shorthand among Undertale fans for a character who cannot quite be trusted, keeping it popular long after players first met him.