Bob-omb Cavern

Bob-omb Cavern is a supposed sub-area of Bob-omb Battlefield, often accessed by going into a hole of the mountain where Big Steelies appear. It is described as round cave with lava in the center that shares it's music with Hazy Maze Cave. The level changes each time a Bowser level is completed.

Before Any Bowser Level
Before a Bowser level is completed, there is simply a rocky platform on top of the lava with a star that has to be reached using a long jump.

Bowser In The Dark World
When Bowser in the Dark World is completed, the single platform will be replaced with several rocky columns that lead up from the lava to a platform with a new star.

Bowser In The Fire Sea
When Bowser in the Fire Sea is completed, the columns will begin to crumble when stood on. There will be a new star at the top.

Bowser In The Sky
When Bowser in the Sky is completed, Blarggs will appear in place of platforms that must be defeated with ways varying with copy to copy. When defeated, a new star will appear.

Bowser In The Randomized Realm
When Bowser in the Randomized Realm is completed, The Blarggs will need to be defeated again, but the crumbling columns will resurface from the lava after the Blarggs are defeated. The player will need to climb the columns for a new star.

Bowser In The Eternal Fort
When the Eternal Fortress is completed when it appears as a Bowser level, a version of Eyerok made out of the rock in the level called the Eyerock will appear that must be defeated for a new star.

Bowser In The Freaky Forest
When Bowser in the Freaky Forest is completed, the lava will not appear but un-moving columns lead up to the new star. This is likely due to most appearances of Bowser in the Freaky Forest being found before the other Bowser levels.

Bowser In The Airship Armada
When Bowser in the Airship Armada is completed, the lava will become blue and there will be blue versions of Blarggs that must be defeated. When they are defeated, the collapsing collumns will appear that lead up to a new star.

Bowser In The Brap Barn
When Bowser's Brap Barn is completed when it appears as a Bowser level, the cave will be filled with Poop-Balls and a Big Braphog. The Big Braphog must be defeated for a new star.