Known as simply Unsigned, it is a monster whos true identity is unknown. It describes itself as a former wandering Earthling and is acquainted with the Professor. It takes on the form of a giant skeleton clad in ancient robes. It has its own army called the Bonenoid, created from using the bones of fallen human soldiers, which it can deploy and summon to fight; rifle-using Bonenoids as covering support, and shield-wielding Boneonids as frontline protectors. Alongside its Bonenoid army.