Cosmic Mario

Cosmic Mario is a character that appears in Super Mario Galaxy. His physical shape is identical to Mario, while his outer appearance is blue with stars all over, as if he were made out of cosmic matter. He also has an unusually high-pitched voice. If Mario or Luigi enter a galaxy when a Cosmic Comet is orbiting a galaxy, Cosmic Mario appears at the beginning at the level and challenges the player to a race. The player must then race through numerous obstacles and reach the finish before Cosmic Mario to earn a Power Star. If Cosmic Mario manages to reach the Power Star first, Mario will lose a life and must restart the race. Colliding with him during the race causes Star Bits to fly out.

If the player is playing as Luigi, Cosmic Luigi will appear in place of Cosmic Mario. Cosmic Luigi utilizes shortcuts and many long jumps. As a result, he is faster and much more difficult to beat than Cosmic Mario.

Similar entities based on Cosmic Mario appear in Super Mario Galaxy 2 in the form of the Cosmic Clones and Cosmic Spirit. Cosmic Clones return in Super Mario 3D Land.

Trivia

 * At the start of a race, if the player holds the up, then  when the timer hits 2, and then hits  just as the race starts, Mario or Luigi will get an extra boost at the beginning of the race, shown by a yellow color appearing on Mario/Luigi, shrinking gradually, being as a marker of the end of the bonus effect. This move is called the Starting Boost.
 * Cosmic Mario shares its voice clips with the Cosmic Clones.
 * An unused variant of the Cosmic Mario Race in Space Junk Galaxy was found in the game files. The problems are when you start a race, you start at the coordinate 0,0,0, which is the air that you land on the starting planet. Cosmic Mario cannot win on this race, and you still have to use Star Chips to unlock a Launch Star, but Cosmic Mario does not need to use the Star Chips to use a Launch Star. Cosmic Mario does not use voice clips in this variant.
 * Cosmic Mario/Cosmic Luigi's theme uses a similar arrangement to Shadow Mario's theme of the same music, the undergound theme from Super Mario Bros..