The Sea of Monsters
Tyson the Cyclops: He is Percy's half brother. He is shown as a homeless child at first. This is before Annabeth tells Percy he is a Cyclops. He goes with Percy and Annabeth to the Sea of Monsters. He becomes friends with a hippocampus. He name it Rainbow. When Clarisse's ship explodes, everyone thinks he is dead. But, Rainbow, the hippocampus, saves him.