The line comes from What's Up?, the 1993 hit by 4 Non Blondes, whose chorus asks what is going on. In 2005 animator Slackcircus edited footage from He-Man and the Masters of the Universe into a flamboyant cover, and the clip spread widely on YouTube under names like HEYYEYAAEYAAAEYAEYAA. Its camp performance turned a nineties rock chorus into a reusable internet greeting and reaction. It remains popular because the elongated hey works without context, instantly signalling silliness, confidence and mock drama in edits, remixes and message threads.