Bosses in Super Mario Galaxy
Baron Brrr[edit]
The sole boss of the Freezeflame Galaxy, Baron Brrr is a pine cone-shaped chunk of ice that appears near the summit of an icy peak in the mission The Freezy Peak of Baron Brrr. Upon reaching the summit, Baron Brrr will hurl balls of ice at Mario, though walls placed around the arena will provide protection. Mario must sneak into a cove beneath the baron's platform to grab an Ice Flower and climb up to battle him.
After Mario reaches the throne, Baron Brrr will slam the ground and create a shock wave that will throw him right back off. The plumber must dodge the wave and spin into the baron to break his exterior layer, then spin into him again to do damage. When the baron recovers, he sprouts a pair of Ice Bubbles to provide interference; however, hitting him only two more times will destroy him and free a Power Star.
Bouldergeist[edit]
Bowser[edit]
Bowser Jr.[edit]
Bugaboom[edit]
Cosmic Mario[edit]
Cosmic Mario is a dark doppelganger of Mario along the same lines as Shadow Mario, though he appears to be composed of space itself rather than water. He appears in four levels of Super Mario Galaxy, where he is created by the presence of a Cosmic Comet flying near that particular level. During these missions, Mario must race Cosmic Mario to the end of a short course to reach a Power Star. If Cosmic Mario gets to the Power Star first, however, Mario loses a life.
While playing as Luigi, Cosmic Mario is naturally replaced with Cosmic Luigi. The course and overall objective of these missions is the same. However, Cosmic Luigi moves somewhat faster than Cosmic Mario did and frequently long jumps to give himself a greater lead.
The four galaxies that Cosmic Mario and Luigi will appear in are: