Dracula vs. Frankenstein (1971)

Judith Fontaine (Regina Carrol) is looking for her sister Joanie, who has disappeared into the hippie community of Venice, California. It turns out Joanie has become the victim of Groton (Lon Chaney Jr.), an ax-wielding homicidal maniac working for Dr. Durea (J. Carrol Naish), who is really the last living member of the Frankenstein family and is now both running a house of horrors on the beach's boardwalk and performing experiments on Gorton's victims. One night, Count Dracula (Zandor Vorkov) visits the mad doctor, showing him the original Frankenstein Monster that was buried in a nearby graveyard. The doctor revives the Monster and uses him to take revenge on his professional rival, Dr. Beaumont.