From the Super Mario Wiki
RAAAARRRRGGGHH (originally formatted as Raaaarrrrggghh) is one of Kat and Ana's microgame found in the Nature folder in WarioWare, Inc.: Mega Microgame$!, and later in Dribble and Spitz's set in WarioWare Gold.
The objective of the game is to help the monster scare off the innocent people, by moving towards their general direction.
In WarioWare Gold, the monster was changed from a brown, mammalian-like creature to a green ogre.
Names in other languages