In the first Super Mario Maker game, this item could only be accessed when an Amibo was used. This power-up had a major effect on a level. For starters, Mario grew from his either 1x1 blocks or 1x2 blocks size to 2x2 blocks. His movements slightly slowed down and he gained the ability to smash hard blocks, Brick Blocks and ? Blocks just by jumping into or onto them. In addition to all this, enemies began appearing differently when Mario took this mushroom. For instance, a Dry Bones will now wear a hat and have Luigi riding on their backs. However, despite these abilities Mario will revert to his Super Mario form if he touches anything harmful, and he is still vulnerable to lava, being crushed and falling through gaps.
This had the same effect in the second Mario Maker game, though the appearances of enemies did not change and every character could use it. In this game, it is automatically accessible and can be found when a player selects a mushroom and holds it.