Weird Mushroom

The Weird Mushroom is a new power-up that made its debut in Super Mario Maker. Upon use, Mario will turn slimmer and gain the abilities of Luigi, with higher jumps but lower traction. It looks similar to a normal Mushroom with a short cap and a very thin base. There is a small chance that they will spawn from a block that normally spawns a Super Mushroom. A Super Mushroom can't overwrite the effect of this mushroom.

According to Tezuka, this power-up was originally a bug while developing the Super Mushroom which made Mario skinny, but he later decided to keep it in the final version of the game as a joke.

To unlock the Weird Mushroom for real, you must complete the 4 Nintendo World Championship 2015 courses at least once, in any order. After clearing them all, a message will pop on the Sample Courses page saying: "Congratulations! You cleared all four of the Nintendo World Championship 2015 courses! Proving your skills as a super player surely deserves a special reward. Next time you're making a course, choose the Super Mario Bros. game style, select a Super Mushroom, and give it a shake...".

After that, the Weird Mushroom by shaking a Super Mushroom in the Super Mario Bros. game style any time one wants.