P-Wing Cap

The P-Wing Cap is an anomalous power-up found in some copies of Super Mario 64. It is a more powerful version of the regular Wing Cap found in the base game, with the name believed to be a reference to the P-Wing from Super Mario Bros. 3. It also typically comes with a cosmetic effect, making Mario’s hat and shirt appear shinier, and adding the sparkle usually seen when riding a Koopa Shell.

Function
The P-Wing Cap, for the most part, acts similarly to the base game’s Wing Cap, but with some improvements such as being able to fly in any direction without stopping, and the timer for the cap wearing off being extended or removed entirely, only removed upon death or exiting the level. However, some reports claim that the P-Wing cap can also act completely differently, behaving more like the Super Leaf or the Cape Feather, from Super Mario Bros. 3 and Super Mario World, respectively.

There are also some reports of the P-Wing Cap granting the ability to launch yourself in a manner similarly to being shot out of a Cannon, before returning to normal Wing Cap behavior in the air.

Unlocking
Many reports have claimed that unlocking the P-Wing Cap involves pressing an alternate, shiny version of the Red Switch, the switch that unlocks the regular Wing Cap. The way to unlock it has been described to usually involve collecting all 120 stars, but some reports, usually those with more courses, claim that it can be unlocked with differing amounts of stars. Some reports even mention the P-Wing Cap outright replacing the Wing Cap entirely.

The location with the P-Wing Cap Switch has been claimed to either replace the normal Tower of the Wing Cap entrance on the 1st Floor after it has been unlocked, with the ray of light reappearing, or appear on the 3rd Floor with a ray of light appearing there in a similar manner.

The course itself has been described as either a harder version of Tower of the Wing Cap, or a night-themed variant of the stage.

Theorizing
The P-Wing Cap, due to most reports describing a very complete item, is believed to be a power-up scrapped very late into development, re-implemented by the Personalization AI. It’s believed to either have been a post-game reward, or a replacement for the Wing Cap in a scrapped Easy Mode.