Hammer Mario

Hammer Mario is a form of Mario or Luigi in Super Mario Bros. 3 when he obtains a Hammer Suit. When they have this form, they look like Hammer Bros. and are able to throw hammers. They also can resist fire attacks when ducking and can defeat most enemies, even Bowser. They gain an infinite supply of hammers, just like Hammer Bros.. While the suit appears to thoroughly protect Mario or Luigi, it does not defend against the simplest of attacks and will be lost in one hit.

This form is not to be confused with Mario or Luigi wielding a hammer, with the difference being the infinite supplies of hammers and the black shell armor.

Trivia
If Mario or Luigi beats a Koopaling while in this state, the king of the world will say:

"Hey, you! How about lending me your clothes? No dice?! What a drag."