Scuttlebug Cavern

Scuttlebug Cavern is a cave level similar to Hazy Maze Cave and other anomalous levels such as Pit of Peril and Deep, Deep Void found in some personalized copies of Super Mario 64. The level contains several Scuttlebugs, hence the name, and commonly uses several other variants of Scuttlebugs via Enemy Discoloring. The level reportedly replaces Hazy Maze Cave, though can be found through other means such as finding a trapdoor in the basement of Princess Peach's Castle or accessing the level in the Below the Castle area. Notably, several reports state that the level has 2 entrances, each with a separate part of the level.

Description
Scuttlebug Cavern's main area is described as a cave made up of several square rooms filled with the titular Scuttlebugs and occasionally other enemies such as Mr. Is, Boos, Swoops and Monty Moles. The rooms are usually otherwise empty except for red coins and secrets if they are present. Some people have reported platforms leading up to stars or nothing on the edges of these rooms, though these reports are unconfirmed.

The second area of Scuttlebug Cavern can reportedly be found through a secret entrance somewhere else in the game, and is described as a large maze filled with poisonous gas similar to the poison maze segment of Hazy Maze Cave. This area usually does not have any safe zones, though few have reported that climbable poles have appeared in the level that lead up out of the gas with some coins to regenerate health.

Stars
The most commonly reported stars are 8 red coins and 5 secrets stars. The other stars usually reported in the main area of Scuttlebug Cavern are stars for climbing platforms along the edge of the rooms, stars for defeating a Big Mr. I, and stars for defeating a Big Boo or Big Boos, likely due to the corresponding enemies reportedly appearing in Scuttlebug Cavern. The stars reported in the second area are usually found by reaching the end of the maze, and finding a hidden area known as the "Queen's Nest" containing a supposed Queen Scuttlebug boss fight, with the appearance of a large pink Scuttlebug constantly spawning other Scuttlebugs. Some have compared this to the Creepy Crawly Queen boss fight in Pit of Peril, leading some to believe that Scuttlebug Cavern is created through Dynamic Level Arrangement and is loosely based off of Pit of Peril.

Report 1
This video by Youtuber First Name Last Name was the first video documentation of Scuttlebug Cavern. It begins in Princess Peach's Castle before entering Hazy Maze Cave, which is now replaced with Scuttlebug Cavern. They only show the first 2 missions, which are named Top of the Cave and The Scuttlebug's 8 Coins, which is the mission which is selected. This version of the level is split into 2 separate chambers, both containing Scuttlebugs and 4 red coins. There are several Scuttlebugs that jump out of the ground as well as a floating Mr. I. The player goes down the hallway to the second chamber, looking up to see a star at the top of the level and out of reach, presumably the Top of the Cave star. They collect the 8 red coins, collect the 8 red coins star, and the video ends. Eventually, a second video documenting Scuttlebug Cavern was uploading, showing the third mission, Queen Scuttlebug's Nest. The player enters Scuttlebug Cavern, notably without any Scuttlebugs spawning, before running into a warp on a wall leading to a sub-area believed to be the titular Queen Scuttlebug's Nest. Inside are several pink Scuttlebugs believed to be "Queen Scuttlebugs," with a star at the end of the area. The description states that the pink Scuttlebugs are likely a result of the Personalization A.I. attempting to recreate a Queen Scuttlebug boss fight though failing and instead recoloring regular Scuttlebugs. Recently the third and likely final video on Scuttlebug Cavern was uploaded, with the player, now playing as Luigi, entering Below the Castle through the entrance to Vanish Cap Under the Moat, notably open despite the moat not being drained, and entering a hole in the ground leading to Scutlebug Cavern. This part of the level has 3 missions: The Scuttlebug Statue, Climbing The Cavern, and The Scuttlebug's Secrets, with the first mission, being the 4th overall Scuttlebug Cavern mission, being the one selected. This area consists of a central room with several Scuttlebugs, a platforming section on one edge of the wall, a statue of a Scuttlebug in the center of the room, a Wing Cap box, and a long hallway above a void with several pillars sticking out of the wall and another area on the other side of the room. The player kills all the Scuttlebugs and collects 5 secrets, spawning a star on the other side of the hallway, before jumping on top of the Scuttlebug statue and collecting the star on top of it as the video ends.