Jeffrey Jeff Fungus is the (former) tertiary antagonist of Monsters, Inc. He is one of Randall's former henchmen.After Randall's banishment and Mr. Waternoose's arrest, Fungus is a lot happier and reforms, also being forgiven by his current boss Sulley for plotting with Randall before.His first name Jeff was first revealed in Monsters University.Fungus is often thought to be a (former) minor antagonist in the first film.He is voiced by Frank Oz by in the films and by Greg Berg in the video games.