A nerdy high school super whiz experiments with a chemical which will transform his guinea pig Mr. Mumps from a gentle pet into a ravenous monster. In a fit of rage against his tormentors at the high school, Vernon Potts (Pat Cardi) goes on a killing spree, eliminating all of those who ever picked on him - the Gym Coach, the School Jock, The Creepy Janitor (Mr. Griggs) his hated teacher, Ms. Grindstaff. In the end he gets the jock's girlfriend for himself but his happiness is short-lived as the potion turns him into a monster hunted by the towns lame police Lieutenant - Bosman.