Bio: Criminal who made early use of microwaves to carry out his robberies. He was then picked up by friendly aliens who had detected his microwave transmitter and spent forty years travelling around the universe before being returned to Earth.
When he discovered the existence of Superman, he asked his alien friends to rejuvenate him so he could battle the Man of Steel at the peak of his powers, even though he knew this would mean his own death. The aliens agreed to this, but also informed Superman of the situation, which led to him deliberately losing the battle so Microwave Man could die happy.