Tyke

Tyke is a sentient star character that Princess Rosetta gives to Mario to assist him in Super Mario Galaxy. She asks Mario to save the Grand Star and then gives Tyke to him as an aid. Tyke is then absorbed into Mario, giving him the ability the do a Star Spin. Some fans have speculated Tyke is on the box art for the game, which features Mario and a single Star that resembles the character. However, this has been proven false by the fact that Tyke is white, while the star on the cover is yellow.