|Item needed||! Block|
|Power(s) given||Armor, inability to fly via cape|
|First appearance||Super Mario-kun volume 1 (1991)|
Chased by a homing, flying hammer, Mario runs on top of a tower of ! Blocks, hoping to escape from it, but the hammer still follows him and pounds him inside of the top block, then destroys the tower. Mario, still stuck in the block, falls on the ground. Mario is laughed at by Luigi and Yoshi and, angry at them, pops his arms and legs out from the block and punches them both.
Mario comes up with a plan: using his new block armor, Mario can jump at the Amazing Flyin' Hammer Brother they have been fighting until now, hide in the block when hammers start raining, and then reach him and defeat him. Unable to use his cape and still inside the block, Mario uses a trampoline and puts his plan into action, but the hammers overpower Mario's block and he falls to the ground, hurt by the hammers and with the block armor destroyed.
Wearable blocks similar to the Block Mario form have appeared in future Mario games, including the Coin Box in Super Mario 3D Land and Super Mario 3D World and the Gold Block in New Super Mario Bros. 2.