Dr. Mentaur is a Human evil scientist who hypnotizes a young woman through hypnosis, a super serum, and metal wings and gives her a costume similar to Birdman thus creating Birdgirl. He explains that Birdman is evil and uses her to trap Birdman. He then causes Birdgirl to steal a hydrogen bomb from the U.S. Government. Mentaur is destroyed by a shell that Birdman deflects back at him. Eventually he was defeated and Birdgirl became normal again.