Musty, Dustyleaf and Thumperfoot's oldest son, leaves his family in search of his purpose. He goes off to be a pet, thinking that was his purpose in life. In his first few days, he finds his owners Dad has a drinking problem. Months pass by before things begin to get heated. His owners Dad begins abusing him, to the point of nearly killing him. Luckily, Dustyleaf was nearby and saved him. He takes him back to Thunder Pack. Musty regrets his decision and lives with the guilt of leaving, only to be abused by somebody he loved and trusted. He works his hardest to become the best Warrior there is, just to prove himself worthy of something. He finds later on that being a Warrior was his purpose all along.