The Blood Beast Terror (1968)
Also called The Vampire Beast Craves Blood. Peter Cushing called this his worst film. In Victorian England, Peter is a Scotland Yard Inspector investigating a series of bloody, albeit less than graphic, murders. What he doesn't know is that they are being committed by a huge bat, uh, I mean moth lady created by entomologist Robert Flemyng. With a taste for the blood of young men, the creature is also capable of taking on a human form and passes herself off as the scientist's daughter, Wanda Ventham, the woman who would one day mother Benedict Cumberbatch. British comedian Roy Hudd appears as a goofy morgue attendant.
PS, this movie is not a sequel to Night of the Blood Beast. No alien shrimp babies. Just humanoid vampire moths.
Also watch out for an extended sequence where they take time out of the movie to do a deliberately silly Frankenstein play.