Grubba's Gloomy Circus

Grubba's Gloomy Circus is a supposed course rumored to appear on the 4th Floor. It is a circus-themed level, with Grubba as the boss, though the character first appeared in Paper Mario: The Thousand Year Door, implying Coincidental Character Creation, or that Grubba was created to appear in this level before it was scrapped and was reused in Paper Mario: TTYD.

Geography
Most geography is inconsistent, though the level takes place in a large night-time circus with few colors. There are several tents to enter, with one leading to the boss fight with Grubba. Another leads to a path into the basement, a large maze that has to be navigated by grabbing and holding a torch from the wall to light the path. A third tent contains a house of mirrors, functioning as a maze.

Missions
"1. TOP OF THE TENT""2. THE A-MAZE-ING BASEMENT""3. MIRAGES IN THE MIRRORS""4. RED COINS AROUND THE CIRCUS""5. 5 SECRETS IN THE HOUSE OF MIRRORS""6. GRUBBA'S GRAND PERFORMANCE""7. 100 COIN STAR"

Top Of The Tent
In this mission, the player has to get on top of a tent in the level to find a star.

The A-Maze-Ing Basement
In this mission, the player needs to find the star at the end of the basement maze.

Mirages In The Mirrors
In this mission, the player has to find a star in the house of mirrors. There are several fake stars seen in the mirrors in this mission, as well as Boos that are only visible in the mirrors but can attack the player.

Red Coins Around The Circus
In this mission, the player has to find 8 red coins around the main part of the map. Notably, red coins commonly never appear inside the tents.

5 Secrets In The House Of Mirrors
In this mission, the player has to find 5 secrets in the house of mirrors for a star. These secrets can be seen in the mirrors as varying objects, often coins.

Grubba's Grand Performance
In this mission, the player has to enter the tent that contains the Grubba boss battle, and defeat Grubba. They function similarly to Bowser, but they are instead thrown into one of the Unagis jumping around the edge of the arena. This must be done 3 times to defeat them. They most commonly drop this mission's star, though some have reported them dropping a key, likely due to their similarities to Bowser. The key's use varies, though it is often useless. It is believed Grubba was built off of Bowser's model and boss fight mechanics, and the key is a remnant of the Bowser model used as a base.