Baron Brrr is a boss in Super Mario Galaxy appearing in Freezeflame Galaxy. It is presumed he is the leader of Li'l Brrs. He resembles Chief Chilly and the Crystal King. The first star of Freezeflame Galaxy is the only mission he appears in.
Baron Brrr makes his first appearance in the mission intro, which shows the camera panning up his home planet until it reaches the boss himself.
He is a large Li'l Brrr wearing a gold crown with hot pink crystals. Inside the crown is a hollow opening that he shoots his ice out of.
Baron Brrr is fought after Mario makes his way halfway up the snowy mountain during the first mission "The Frozen Peak of Baron Brrr." From a distance, Baron Brrr will shoot chunks of ice at Mario that could damage him. When Mario is up close, Baron Brrr will crash onto the platform and send out shockwaves that could damage Mario and knock him off the platform and into the icy-cold water if they come in contact with him. On his final phase he will summon two Li'l Brr's to gang up on Mario.
In order to reach Baron Brrr, Mario must grab an Ice Flower to become Ice Mario and skate his way across the icy water and Wall Jump up to his platform. Mario should carefully jump over the shockwaves and attack Baron Brrr with a Spin. After Baron Brrr has been hit, he will attempt to get back his icy armor by rolling around in the snow. This is Mario's chance to use another Spin attack to effectively damage Baron Brrr. If Mario repeats this process two more times, Baron Brrr will be destroyed. Mario is awarded with a Power Star.
- Due to his defeat (however he is not dead because what Mario and Luigi didn't know is that when he exploded his ice chunk parts landed in the water and he reformed. Nintendo revealed this at a special meeting about the particularly good sales of Super Mario Galaxy) in the first game, Baron Brrr does not appear in the sequel. However, his battle theme is remixed when Mario fights King Lakitu and the Mandibug Stack in Super Mario Galaxy 2.
- Even though "The Frozen Peak of Baron Brrr" is the first mission, Mario can actually ignore the fight with Baron Brrr and go to the other side of the mountain to complete the secret mission "Conquering the Summit" first.
- Baron Brrr's name is based on the 3rd vice president of the United States Aaron Burr.
- His battle theme is reused when you fight the Undergrunt Gunner in the Deep Dark Galaxy.
- It is possible that his appearance was based off of Chief Chilly from Super Mario 64 DS and Mario Kart DS.