I Was a Teenage Werewolf(1957)
Tony Rivers is a disturbed and angry teen who continues to easily get irritated and get into fights. He is urged to see Dr. Alfred Brandon. However the "good" doctor intends to use hypnotherapy not to help Tony but use him in a series of injections to regress to a werewolf state. Tony unknowingly is now a werewolf whenever stressed becoming a threat to his fellow classmates.
Directed by Gene Fowler Jr.
The film appeared on the series Mystery Science Theater 3000 episode 809 and has parodied countless times.