Robert Mason was the captain of the Gray Tiger; a Behemoth-class battlecruiser. He was loyal to the ship despite its rugged exterior and interior and would hear no word against it. Mason was tall, thin, had greasy blond hair, uneven, off-white teeth and "looked about as dented and dirtied as the vessel he captained." He also possessed exceptionally pale skin and had dark smudges under his eyes, probably as the result of receiving little sunlight due to his service.