Hammer Bro.

A Hammer Bro is one of the original characters in the game Super Mario Bros. for the NES. The enemy usually comes in twos, and they will constantly throw hammers at you. They are counted as the hardest enemy other than Bowser to beat, especially when you're not Fire Mario.

Though they haven't appeared in any 3-D Mario platformer, they are in a ton of the Mario sidescrollers, such as Super Mario Bros. 3 and New Super Mario Bros. and Dance Dance Revolution: Mario Mix, guarding the gate to the amusement park. They've also appeared as a playable character in the game Mario Superstar Baseball, on Bowser's team and in Mario Strikers Charged as an offensive sidekick, a character that is good at passing and shooting. They also appear as an assist trophy in Super Smash Bros. Brawl.

A Hammer Brother is a playable character in Mario Party 8, but it has to be unlocked first. A hammer Brother is also an enemy space in Mario Party 7.