P-Acorn

A P-Acorn is an item in New Super Mario Bros. U. It transforms its user into P Flying Squirrel Mario with the ability to midair jump indefinitely for the entire stage, similar to the P-Wing and Cape Feather from previous games. Its appearance is similar to the Super Acorn, but the top is pale white and gray-striped, with a large, red "P" imprinted on it. In Mario's case, his hat and shirt become pale gray; his hat has a large, red "P" instead of his "M" emblem; and he also appears to have a sheen around him. The P-Acorn's power will disappear if the player loses a life, takes damage, grabs a non-Acorn power-up, or completes a level without losing the power-up (the latter of which causing the player to change to the regular Flying Squirrel form). However, the player will not lose the power-up if the course is completed via capturing Nabbit.

To obtain a P-Acorn, the player must either capture Nabbit and return his sack to a Toad, or after defeating Bowser, if the player saves their profile then opens it again, a P-Acorn will appear instead of a Super Acorn (it also seems to appear at other times). A P-Acorn can appear sometimes on the main map in the place of a Super Acorn. Another way to obtain a P-Acorn, with a very slim chance of doing so, is that sometimes, in the middle of Tilted Tunnel and Crushing Cogs Tower on the world map, it is either this power-up or the Super Acorn (which is more common) that appears.

The P-Acorn also grants the player access to shortcuts that completely skip underground sections of levels by flying over the top of the screen past the pipe leading underground, which is otherwise not possible with a normal Super Acorn or even a Propeller Suit. A few levels that allow these shortcuts are Tilted Tunnel, Fire Snake Cavern, Tropical Refresher, Icicle Caverns, and Shifting-Floor Cave.

The player would have not been able to make a Miiverse post if a level was completed with this power-up, even if the level was cleared without taking any damage. This would have been the same if the level was completed while playing as Nabbit in New Super Luigi U.

The sound effect heard when flying through the air in this form is the same one heard when flying as Raccoon Mario.

New Super Mario Bros. U Deluxe

 * North American website bio: A rare variety of the Super Acorn that gives unlimited flight ability through a whole course (or at least until an enemy hits you).

Play Nintendo

 * New Super Mario Bros. U Deluxe Power-Ups Trivia Quiz : The P-Acorn gives unlimited flight ability through a whole course (or at least until you take damage).