- "You. Finally, I get a piece of you. Finally, we'll see who's truly stronger."
- ― The Koopinator
He is a Dark Koopatrol, but has differently shaped eyes. There are only two Dark Koopatrol in the game: one in the Pit of 100 Trials, and the Koopinator. He has stronger attacks than normal Koopatrol, more health, the "dark claw attack", but he can not call reinforcements. He is the highest-ranked member of the arena's major-league and only surpassed by the champion, Rawk Hawk himself.
Mario first encounters the Koopinator when he travels to Glitzville in search of the Gold Star in chapter three. When entering the Glitz Pit for the first time, Mario and his partners witness an official match between the Koopinator and Rawk Hawk. Rawk Hawk however manages to defeat the Dark Koopatrol without much effort, thereby defending his rank. The fight plays a key role in inspiring Mario to become a contract fighter, because the Gold Star is introduced in that scene.