Birdgirl was created by Dr. Mentaur through hypnosis, a super serum, to destroy Birdman. She was an aerialist before she met Dr. Mentaur. While under hypnosis, she was given some metal wings and a costume similar to Birdman in order to defeat him. While captured, Birdman tricked her into letting him go outside as a last request. Thus, regaining his strength from the sun, this allowed Birdman to defeat Dr. Mentaur and save Birdgirl. Birdgirl realized she served a madman and soon after became a force for good.