Mr. Skeleton

Origin
Mr. Skeleton is a huge, demonic undead creature standing approximately 20 feet tall, thin with bone-white skin. It possesses superhuman strength, sufficient to pick up several men in one of its giant clawed hands with ease. It is extremely difficult to injure, much less kill and it is completely invulnerable to bullets from conventional firearms. It is capable of charging into a military base and killing soldiers by the dozen. It has human intelligence and was probably once human, but it seems to be motivated by little more than its own lust for death and destruction. At one point, it sent a thug to assassinate the president of the United States. Later, it personally went about capturing US generals and other military personnel which it brought back to its den and dipped in an acid bath, reducing them all to skeletons. It was eventually broken into a pile of bones by the Minute Man, though it had proved more than a match for him on their first encounter.