just a very skinny skull. probably starvation.
Think about this:
Kids where harvested for organs and adrenochrome.
Modern pop culture referenced this right in your face but people did not know what they were seeing. In order to harvest Adrenochrome, one eye is usually removed from the skull of the victim and the pineal gland taken directly out of the socket.
Adrenochrome junkies like Madonna even referenced this shit in their outfits by wearing a "stylish" eyepad for no reason.
so how do you harvest :)
cracking and sawing open the skull, taking the brain out?
or drilling behind the eyesocket?