A Cusimonster is a person who turns into a beast after drinking excessive amounts of Monster, Redbull, Venom, or Rockstars. A Cusimonster is a typically awesome person, just don't piss them off.
Person 1: Yeahhh, i drank a Monster--
Person 2: And you turned into a Cusimonster Right??
Person 1: Hellyazzzz!
Person 2: And you turned into a Cusimonster Right??
Person 1: Hellyazzzz!
by runnn! May 8, 2010