The Yellow Devil is a large robot of unusual design. Created by Dr. Albert W. Wily, it guards the doctor's fortress in the original Mega Man game and its remake Mega Man: Powered Up. Its body is made up of a semi-solid, yellow substance that can alter its consistency, becoming as soft as pudding or hard as rock. The Yellow Devil attacks by launching portions of its mass at Mega Man, disassembling itself and then reassembling itself on the other side of a room. The yellow substance is invulnerable to any of Mega Man's collected weapons. Only the creature's eye is vulnerable, but even then can only be damaged by some weapons. Elec Man's thunder Beam is the most effective weapon to use against this enemy.