Hammer Bro., also called Hammer Brothers or Hammer Bros., is an enemy from the "Mario" series of video games. It is a type of Koopa Troopa that walks on two feet and attacks by throwing hammers at the player character. There are different types of Hammer Bro. that are named after the attack that they use, such as the Boomerang Bro. and the Fire Bro. The Hammer Bro. has appeared in many "Mario" games since its first appearance in "Super Mario Bros.", including spin-off games such as the "Mario Party" games.