The Skeletoids were suits which could take over their wearers. They required a living human in order to function. These humans would be mind-controlled and preserved by the suit, though they would look like decayed corpses.
They emerged as a serious threat to even the Daleks and the Cybermen. They swept across two empires, taking prisoners. The strong were fitted with suits, becoming as they were. They finally came to the Draconian Empire and were destroyed by Abel Gantz. (COMIC: Kane's Story, Frobisher's Story)