THE VAMPIRE HAPPENING (1974) - A.K.A. Gebissen wird nur nachts. This is a very fun German Erotic Vampire Comedy. It's a little like THE FEARLESS VAMPIRE KILLERS, but on the Erotic side with monks, priest, students, and even an appearance of Count Dracula himself in the final orgy. Again this film is alot of fun and be "warned" of the excessive nudity content.
I bought this on DVD a couple of years ago. The helicopter with the bat logo on it is pretty funny.