Knuckles the Echidna is one of the main characters that appears in the Sonic Boom series. He is an anthropomorphic echidna from Angel Island and the last of his kind. He is also the keeper of the Fregosi Sapphire. Knuckles serves as the muscle of Team Sonic, a group of heroes who defends the peace of Seaside Island and the world at large. Unlike his friends, Knuckles is a nomad without a permanent home and lives in nature.