Nekukakos is a high ranking demon among his kin.
He is brother to Mortmercaton and Nekradonna.

When Nekukaos first entered the human realm he had no physical form. To gain one he possessed a human and pushed out the soul. From there he dimembered his own newly found body and replaced parts with what he wanted from other creatures.
Now his body is nothing more than bones he has gathered over the centuries. He puts the parts together as he sees fit so his structure can vary, but he tends to have human arms and a bovine or equine face.
Once complete, his body begins to degenerate. The skin rots away, then the flesh unravels and some of the bones crumble. During these times Nekukakos will use strips of dried leather and old cloth to keep himself together.
Eventually he performs a ritual which restores the flesh, viscera, and skin, but he is forgetful. He devotes his time to studying biological structures and that includes those that are not seen by the human eye. He dissected other demons as well as angels, mythical creatures, and other oddities.

His true demonic form shows itself within his demonic aura that surrounds him. It does strange things to the atmosphere near him and warps reality. For example, his shadow will move on its own sometimes or things will levitate across the room.

His mind is as rotted as his body. He will babble to himself and lick his putrid tongue across his uneven teeth while he studies whatever organ or body part he has been able to find.