After watching I was a Teenage Werewolf (1957) at a drive in with you and Sam to relax after a case, Dean has a nightmare that he’s turned into a werewolf. He dozes off in the motel after the movie and is transported into the dream. Dean looks down at his hands which are now fuzzy and hairy. He has long grotesquely looking fingernails and his fangs. Hes growling at his reflection when you come into the motel room Dean: Stay away!