Hammers are Mario's basic weapons in the Mario & Kirby: The Hope of All Realms series. Mario uses them to smash buttons, steaks, enemies and break into castles. They look like real-life hammers. Kirby uses them when he copies the Hammer ability by eating a hammer, Hammer Bro or any other enemies who uses a hammer in combat.

Luigi also uses a hammer which is the exact same hammer that Mario uses.

The artwork of a Hammer.