Co-Star Luma

The Co-Star Luma is an orange Luma that appears in Super Mario Galaxy 2 as a playable character. The Co-Star Luma appears alongside Mario in the cooperative two-player mode (Co-Star Mode), in which the second player is able to control it using the Wii Remote. The Co-Star Luma can perform moves such as the Star Spin, and in addition to collecting and shooting star bits just like the first player can, can also perform other actions that a single player cannot, such as temporarily immobilizing certain enemies or barriers, and picking up far-away objects, including 1-Up Mushrooms, air bubbles (when underwater), and coins, which the Co-Star Luma will then bring back to Mario. The Co-Star Luma can also perform a variety of other actions, including activating switches or other objects, touching Spiky Plants, causing them to retract their spikes, and spinning regular Lumas (excluding Lubba) to receive star bits. If there isn't a second player, then the Co-Star Luma will appear on Starship Mario.

Trivia

 * The player controlling the Co-Star Luma can make sounds on his/her Wii Remote (as well as player one's) by pressing buttons on the remote.
 * The Co-Star Luma is similar in function to the 2nd player cursor (which is also yellow) in Super Mario Galaxy.