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. The game's prologue shows Princess Peach holding Tyke when Bowser attacks with his airships. Mario is then given Tyke by Rosetta when he awakens on the first planet in the Gateway Galaxy.