Courage is a pink dog who is constantly frightened, despite his name. He was adopted by a married couple, Muriel and Eustace Bagge, when they found him abandoned in the middle of Nowhere as a puppy when his parents were sent to space by a mad scientist. While Muriel loves him, Eustace calls him "Stupid Dog" and frightens him for his own amusement. However, he will protect his owners (mainly Muriel and even Eustace in some instances) with his life.
During the Planetoid Fusion crisis, Courage (with the help of the Hero) is ultimately the one that destroys the planetoid by reversing the polarities of a UFO magnet found in Nowhere which was pulling the planetoid to Earth. With the polarities reversed, the Planetoid Fusion was crushed by its own force and was succesfully destroyed before it reached Earth. It is hinted that at least Muriel is hiding in the farmhouse, as Courage had the player retrieve her slippers from monsters as a Guide Mission from Edd ("Slippery Foes").