An American actor. He has appeared in several horror movies and other B movies. Berryman is famous for having a distinctive physical appearance as a result of hypohidrotic ectodermal dysplasia, a rare genetic condition which prevents him from developing hair, sweat glands or fingernails. According to his own statements in an interview for the DVD release of The Hills Have Eyes, he was born with "twenty-six birth defects."

Description above from the Wikipedia article Michael Berryman, licensed under CC-BY-SA, full list of contributors on Wikipedia