While this was not Hammer's first foray into horror where the "monster" was a woman - see also things like The Gorgon - it predates by four years their full-blown 1971 trilogy of such things (the two linked below, plus Countess Dracula). However, the title is inaccurate: the Baron (Cushing) doesn't "create" anything much here, least of all a female; and particularly not one in a bikini, as depicted by the poster! He has moved into the business of soul transference, and seizes his chance when young assistant Hans (Morris) is wrongly guillotined for murder, and his somewhat-disfigured girlfriend Christine (Denberg) commits suicide. Using both bodies, he and assistant Doctor Hertz (Walters) move Hans's soul into Christine, bringing her back to life; curiously, the process turns her blonde. But Hans has not forgiven the trio of toffs who were the real killers, and is intent on exacting revenge on them - even if he has to use Christine's body to do it.
I liked this one. It has a metaphysical bent and more thoughtful air, definitely different from the usual "lumbering monster rampage" we'd seen in other entries. There's also something particularly disturbing about Hans being trapped in a woman's body, and coming on to other men for revenge purposes. Never mind murder: following through and sleeping with them, then announcing who s/he really is would probably be more traumatic. The Baron is just about innocent here, and not responsible, directly, for anyone's death. Indeed, when he realizes what is going on, Victor tries to warn the locals, and when they (somewhat understandably) don't believe him, sets off to stop Christine/Hans himself. If there are gaps in the narrative e.g. why Frankenstein is apparently unable to use his hands, this is a highly-enjoyable combination of horror and romance, with some surprisingly deep philosophical tones to enhance the flavour.