Hammer

The Hammer is an item that appears only in a few games in the Donkey Kong frachise. In all of its appearances in the series, it is only used by one character.

Donkey Kong (1981)
In Donkey Kong (1981), the hammer is used by Mario as a collectible power-up. After grabbing the hammer, Mario can break through the Barrels Donkey Kong throws at him, as well as destroy obstacles in his path. Mario is not completely protected however, as he can still get hit from the back, and lose a life.

DK: Jungle Climber
In the Nintendo DS game DK: Jungle Climber, the hammer is one of Diddy Kong's attacks, along with Torch. The hammer can be used to defeat enemies, smash walls, and help the Kongs progress in the levels.