Call Me Tonight (1986)

As a call girl, Rumi’s used to dealing with perverts of all stripes. But her latest caller, the helpless Ryu, isn’t like the rest: Turning him on transforms him into a vicious monster, complete with razor-sharp teeth, claws, scales, and tentacles. Rumi’s up to the challenge, of course — but as she gets closer to helping Ryu handle his special problem, she finds out she’s not the only one who wants a piece of the action.