Magical muscle beings who have skulls for heads. They have attempted to integrate themselves into skeleton society, but have been shunned for only partly exposing the Bonner Within, and remain outcasts. It is said that all skeletors descend from a common ancestor named Skeletor whose face accidentally got splashed by really hot oatmeal and was reduced to a skull. Somehow, this became ingrained in Skeletor's genetic makeup, and his progeny have been unable to escape its curse.

Skeletors live in dark places, thinking that the combination of their their skull-heads and dimly lit conditions will scare the daylights out of adventurers. They are severely mistaken, and mostly die to unfazed heroes in under five seconds. A fraction of natural philosophers believe that skeletors lack brains; the other fraction believes that a skeletor's brain dissolves upon death. Exploration of either hypothesis has been difficult.