The Hammer Bro (plural: Hammer Bros. or Hammer Brothers) is a recurring enemy in the Mario video game series. Created by Japanese video game designer Kazuaki Morita, it is a Koopa that walks upright and attacks by throwing hammer projectiles at the player character. Different variations of the character, based on projectiles they throw, include Boomerang Bro, Fire Bro, Sledge Bro, Sumo Bro, and Ice Bro. It has appeared in nearly every Super Mario game since its first appearance in Super Mario Bros., and has also appeared in various animated and printed adaptations.