Big Boo's Key

Big Boo's Key is the name given to an unused key object that would have been found in certain Boos, likely Big Boos, in Super Mario 64. They are assumed to have been found in Big Boo's Haunt, Big Boo's Castle or Big Boo's Forest. They were first seen in some beta footage that currently has not been located (when found, put link here please and edit that sentence). They do not appear to have a programmed use. There is also a second version that appears earlier than the main version. When collected, it does not raise the unused key counter and only emits coin sparks. The keys have also been speculated to be an early version of a Bowser key. However, the A.I. can use it to lock several things.

Alternate Colors
There are 3 other colors than yellow: red, blue, and green. It is currently unknown if these were intended to have any different uses than the regular Big Boo's Key.

Unused Key Icons
Found in the files of the Japanese version Super Mario 64 is an unused key icon in the style of the beta HUD icons. However, in the European versions, it was replaced with a U. No replacement was added to the US version, and it was completely removed. It is believed these icons were intended to be used for a Big Boo's Key counter if there were multiple colors used, or instead displayed on-screen to signify the player had collected a key. However, another theory states these were for Bowser keys and are unrelated to Big Boo's Keys. It is unknown why the key was replaced with a U in European versions. However, personalized copies use these icons in their respective regions, with the Japanese key icon being used in the US versions, for a Big Boo's Key counter.

Uses
There are several uses for these keys throughout the many reports of personalized copies. These include:


 * Unlocking regular rooms of Big Boo's Haunt.
 * Unlocking Big Boo's Forest.
 * Unlocking Big Boo's Castle.
 * Unlocking Big Boo's Haunt, with a door in the Castle Courtyard requiring the key.
 * Unlocking a room with the Giant Boo.
 * Unlocking a room with the Ghoul Medal.
 * Unlocking a room with Luigi.
 * Unlocking the stairs.
 * Unlocking nothing.
 * Unlocking a random floor of Princess Peach's Castle, usually either Floor 2B or the Third Floor.
 * Replacing a Bowser key, and functioning the same.
 * Unlocking regular rooms of Princess Peach's Castle.