I remember this one Night Gallery I think it was, the whole show this girl thinks this guy is a vampire, all the signs point to him being a vampire and the reason folks are dissapearing, finally somehow they confront each other and he shows her himself in a mirror's reflection and is like "see I'm not a vampire" she is relieved UNTIL HE TURNS INTO A WEREWOLF AND EATS HER!!!!

I'd love to see that one again!