Piranha Valley

Piranha Valley is an anomalous level found in some personalized copies of Super Mario 64, often found inside of the 4th Floor of Princess Peach's Castle, particularly the Internal Garden. It takes place in a valley filled with Piranha Plants, hence the name. This level has been particularly noted to be very difficult for numerous different reasons. Piranha Valley's music is reportedly a unique track, though supposedly contains the leitmotif of Super Mario Bros. 3's Overworld theme.

Description
Piranha Valley is a valley area with trees scattered about that is reportedly filled with Piranha Plants, Piranha Flowers, Fly Guys and Keronpa Balls, as well as Goombas, all of varying sizes, similarly to Tiny-Huge Island. A majority of the enemies are abundant throughout the level, being a constant threat that contributes to this level's difficulty. The level is supposedly covered in spikey vines commonly originating from the level's boss, also being a major contributor to the difficulty due to their omnipresence.

Several people have reported either a cave or ravine acting as the secondary area of the level, being a large linear hallway with a bottomless pit and walls made of green rock with similar rock platforms scattered on the walls, allowing for traversal of the area. This area is where most of the vines in the level are located, likely due to most reports claiming that this is the location of the level's boss.

The boss arena is reportedly found at the end of the cavern area, being a large underground lake with a platform in the center the player stays on. The boss itself is a large Piranha Plant with several heads resembling the Lava Piranha, the boss fight of the Mount Lavalava area in Paper Mario 64, as well as the Naval Piranha in Yoshi's Island. They can attack by slamming their heads on the ground, spitting fire, chomping at the player, or throwing vines onto the platform. They are damaged by ground pounding their heads, which reportedly enter the player's reach when they slam onto the platform or go underwater when spitting fire in order to avoid their own attack.

Missions
The most common Power Stars in Piranha Valley are obtained by defeating a group of Piranha Flowers similarly to Tiny-Huge Island, collecting 8 red coins, platforming through part of the cavern area, and defeating the level's boss. A Power Star involving the sky in some way is also common, though the exact method of obtaining the star is inconsistent, with some claiming they needed to use the Wing Cap, a cannon, or Fly Guys in order to reach the Power Star. Less common Power Star are obtained by finding 5 secrets somewhere in the level, and exploring the boss arena after defeating the level boss.