“...and what does Nackles do? Nackles lives on the flesh of little boys and girls... Nackles roams back and forth under the earth, in his dark tunnels darker than subway tunnels, pulled by the eight dead-white goats, and he searches for little boys and girls to stuff into his big black sack and carry away and eat. But Santa Claus won’t let him have good boys and girls. Santa Claus is stronger than Nackles, and keeps a protective shield around little children, so Nackles can’t get at them.
“But when little children are bad, it hurts Santa Claus, and weakens the shield Santa Claus has placed around them, and if they keep on being bad pretty soon there’s no shield left at all, and on Christmas Eve instead of Santa Claus coming down out of the sky with his bag of presents Nackles comes up out of the ground with his bag of emptiness, and stuffs the bad children in, and whisks them away to his dark tunnels and the eight dead-white goats.”
--Donald Westlake as Curt Clark, Nackles