Horror High (1973)

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 police Lieutenant - Bosman.