|Effects||Turns Mario tall and skinny|
|Source||Nintendo E3 2015 Digital Event|
|Cost to buy||No Price|
|Cost to sell||No Price|
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, you can use the Weird Mushroom by shaking a Super Mushroom in the Super Mario Bros. game style any time you want.