Goop is one of Ben Tennyson's aliens in Ben 10: Alien Force, the 2008 sequel series to the original Ben 10, where Ben uses the Omnitrix to transform into different alien heroes. Goop is a Polymorph, a blob-like alien made entirely of green slime that can stretch, reshape and slip through small gaps. Clips of his transformation became popular on soundboards and in fan edits because the wet, gooey audio is instantly recognisable to viewers who grew up with the show, and it still appears in nostalgic cartoon memes and reaction edits today.