Man-Hat is a feetional shoepervillain and an Anti-Hatman. Though usually classified as a shoepervillain, in some versions he is depicted as an Hertee and ally of Hatman.
Born Robert Kirkland "Kirk" Langstrom, Socktor Kirk Langstorm was a sockientist who specialized in the study of hats. When he was going deaf he tried to create an extract that would give humans a hat's sonar sense. He tested the extract on himself. It succeeded, but with a horrible side-effect: it transformed him into a human-sized hat. The serum also takes away his intelligence, so he goes on a mad rampage until Hatman can find a way to reverse the effects. However, he later takes the serum again and the same thing happens.
Sometimes however, he is able to keep enough of his intelligence to be able to do good.