Dry Skulls are the heads of Dry Bones that live on their own without any body. When Mario stomps a Dry Bones in a Ghost House, the skull's pupils turn red and hop around in random directions. The Dry Shell, with the bone limbs and tail are left, until the Dry Skull meets the body in it's path again, as it then can rearrange itself again. Mario can kick the Dry Shell, however, which could act like a normal Koopa Shell, and can defeat the Dry Skull.