Super Crown

A Super Crown is an upcoming item that is scheduled to make its debut in New Super Mario Bros. U Deluxe. So far, the only effect that it is known for is to transform Toadette into Peachette, a Princess Peach lookalike that gives her the ability to Double Jump, and perform Peach's Floating Jump, controlling identical to the Flying Squirrel form (without the wall-clinging ability). Additionally, she automatically gets boosted if she falls into pits. The Super Crown's top appears to resemble the mushroom head of Toadette, being pink with white spots.

Trivia

 * The concept of the Super Crown transforming Toadette into another character and granting her their abilities is similar to that of the caps in Super Mario 64 DS.