Bowser in the Fire Sea

Bowser in the Fire Sea is the second Bowser level in Mario 64. It is accessed in the castle basement, and contains the second Bowser boss fight.

As suggested by the name, this course takes place in a sea of molten magma, similar to Lethal Lava Land. There are a number of floating platforms fixed in the sky, as well as a number of platforms that bob up and down in the lava. Enemies here include typical Bowser level enemies like Goombas and Bob-ombs, as well as Bullies.

When the player defeats Bowser here, he will give up the Key to the second floor. A single star can also be obtained here by collecting the 8 Red Coins throughout the stage.

Blargg
Main Article: Blargg

Blarggs are unused enemies in Super Mario 64, first appearing in Super Mario World. They are referenced in the files to appear in Lethal Lava Land, Bowser in the Fire Sea, and Wing Mario over the Rainbow. They are red dinosaur-like enemies that live inside lava, and jump up to attack the player when nearby.

Podoboos
Podoboos, also known as Lava Bubbles are enemies from the Super Mario Bros. series, first appearing in the first Super Mario Bros. games, that have been reported to appear in Bowser in the Fire Sea. They are bubbles made from lava, occasionally having 2 oval-shaped eyes on them. They jump up from lava when present, and deal damage to the player upon contact. These enemies usually appear as reskins of the regular fire that occasionally jumps up from the lava in Super Mario 64, or as unique enemies that can jump up through unique grate platforms.

Big Bully
Some reports claim that the Big Bully from Lethal Lava Land appears before the end of the level, challenging the player to one more fight before facing Bowser. While this fight is noticeably more difficult due to the smaller platform, it can easily be skipped by walking past the Bully. Defeating it earns you an additional star, making it count as an optional fight.