From the Super Mario Wiki
The Propeller Mushroom (also known as Propellerhead or Propeller Suit) is an item introduced in New Super Mario Bros. Wii. The Propeller Mushrooms is an orange-capped Mushroom with two light-yellow spots and a yellow propeller atop the cap. Obtaining a Propeller Mushroom turns the player into their Propeller form. giving them a character-colored jumpsuit with a large helmet-like cap that has a propeller sticking out of it and the player's emblem emblazoned on its sides. If left alone, the Propeller Mushroom will eventually fly out of the stage.
New Super Mario Bros. Wii
The Propeller Mushroom debuts in World 1-1, and it is one of the main powerups of the game, alongside the Penguin Suit. When collected, the power-up sound will have an additional "spin" effect. As the name implies, the Propeller Mushroom lets the player fly through the air, spinning like a propeller, by shaking the Wii Remote; afterward, they will gently float to the ground, and their descent can be further slowed if the player shakes the Wii Remote while falling. Holding the down button will make the player spin downward like a drill for an attack with the same effects as a Ground Pound. Propeller flight is not continuous, but after the player lands, they will be able to take flight again.
A player can grab onto another player who has the Propeller Mushroom by holding and shaking the Wii Remote; the player with the Propeller Mushroom can then shake the Wii Remote to launch them both into the air. If the player gets swallowed by a Yoshi, they can shake the Wii Remote and fly out of the Yoshi's mouth.
Propeller Blocks work in the same way, though they need to be held, and can be used regardless of the holder's form.
Super Mario 3D Land / Super Mario 3D World
New Super Mario Bros. U / New Super Luigi U / New Super Mario Bros. U Deluxe
This item reappears in New Super Mario Bros. U acting in a similar manner to the Wii version, but the object can only be found in a Toad House from Superstar Road, and the player does not spin around as fast when flying compared to the previous game. In New Super Mario Bros. U Deluxe the Propeller Mushroom acts the same, but can now be obtained from Enemy Courses.
Super Mario Maker / Super Mario Maker for Nintendo 3DS / Super Mario Maker 2
Propeller Mushrooms reappear in Super Mario Maker, Super Mario Maker for Nintendo 3DS and Super Mario Maker 2, exclusive to the New Super Mario Bros. U style. In the nighttime ground theme in Super Mario Maker 2, Propeller Mushrooms fly in random directions a few times before flying away.
Mario Kart 8 / Mario Kart 8 Deluxe
New Super Mario Bros. Wii
New Super Mario Bros. U Deluxe
Names in other languages