Sssssss (1973)

"Sssssss" is a 1973 Horror movie directed by Hal Dresner and starring by Strother Martin, Dirk Benedict. David, a college student, is looking for a job. He is hired by Dr. Stoner as a lab assistant for his research and experiments on snakes. David also begins to fall for Stoner's young daughter, Kristina. However, the good doctor has secretly brewed up a serum that can transform any man into a King Cobra snake-and he plans to use it on David.