Teen Wolf is a 1985 American fantasy-comedy film directed by Rod Daniel and written by Jeph Loeb and Matthew Weisman. The film stars Michael J. Fox as a high school student who discovers that his family has an unusual pedigree when he finds himself transforming into a werewolf.
Mystery Science Theater 3000 Ep. 904 Werewolf (1995) Review
If you ever want to introduce MST3K to a potential new fan, this is an excellent film to start with.