Sounderous is a giant kaiju-like robot and a support ally in the Gridman Universe franchise, associated with the anti-kaiju forces. In SSSS.DYNAZENON and related Gridman Universe works, it functions as a powerful combat and transport unit, often helping the main team in battles against kaiju threats. It is not a human character but a mechanical companion with a distinct personality and combat role, serving as a dependable powerhouse in large-scale fights and team operations.