Dr. Mardock is the villain in Pop n' Twinbee. Apparently, Mardock was a peaceful scientist until he one day hit his head upon a pole and ended up trying to take over the world. Whether this insanity is temporary or irreversible is unknown. He loves rabbits, is fairly unhygenic and lives in a huge mountaintop onto which he's carved the gigantic image of his own likeness. His grand-daughter is Madoka.
He also makes an appareance in Jikkyō Oshaberi Parodius.