The Lost Spikes

The Lost Spikes is the nickname given to a level found in some personalized copies of Super Mario 64. This level is described as a seemingly endless rocky, black and green field with several stalactites and stalagmites scattered throughout the level, being mostly devoid of objects and enemies. The level has been reported to replace Dire, Dire Docks in copies that feature the Shifting Labyrinth anomaly, for other copies the level is said to be accessed by "entering" the skybox of Bowser in the Dark World in some way, shape or form, with some commonly reported methods being using the Wing Cap or pressing a purple! Switch to spawn a bridge of boxes leading into the skybox to the level.

Appearance
This level takes the appearance of a black and green landscape covered in stalactites and stalagmites of varying heights and sizes, bearing resemblance to the skybox of Bowser in the Dark World. The terrain is very rough, and it’s easy to fall into several bottomless pits. The level commonly contains 6 Power Stars randomly scattered around the landscape which, with the exception of the 100 coins star, will not cause the player to be thrown out the level upon collection. The level usually contains neither enemies nor objects except coins and Power Stars, indicating that the level could have been scrapped in a very early state or is entirely generated by the Personalization A.I. However, players with copies that contain the Raven anomaly reported seeing a humanoid raven hiding behind the level's geometry while watching the player, unkindnesses of aggressive ravens have also been sighted gathering around and on the stalactites and stalagmites.

Theorizing
It has been theorized that this level is seemingly endless due to teleporters surrounding the level teleporting the player to the other edge of the level to simulate the level being infinite, or that it was created to test the Procedural Generation anomaly, often associated with levels that appear to be endless. An alternative version of this theory is that the level is entirely created through Procedural Generation based off of Bowser in the Dark World's skybox by the Personalization A.I. instead of being designed by the developers of Super Mario 64. This theory might also account for Big Boo's Forest, a level believed to be genuinely unused and appearing to take place in the skybox of Big Boo's Haunt.