Mike Harper is the main antagonist of Poker Under Arms. He is a skilled gunman and a card sharp player whom Don Peckinpah challenges in a game of poker.
Mike Harper is a lean man with a long face and smooth features, save for a scar on the left side of his mouth. Harper has long, curly, light hair. He wears a light shirt, a dark tie, a spotted vest, and a dark jacket. He also wears a typical cowboy's hat.