Treble is a robotic wolf created by Dr. Wily to assist Bass. He is to Bass what Rush is to Mega Man. Bass and Treble can merge, giving Bass the ability to fly and gain more offensive attacks. In Mushroom Kingdom Fusion, Treble appears during the end-level boss fight Robot Museum, where he helps Bass fight against the player. Treble is also planned to appear in Turbo Turnpike, where he and Bass merge to become "Super Bass" as they assist the player.