I know this ones been done before, but hey, it's the season.
Santa HAS to be LE-neutral, like Archeron.
He uses Greed and Gluttony to get "good" behavior, but then rewards the bad behavers with Coal to keep them warm in winter.
Sounds like a Baatezu / Devil's pact, but with 2 mitigating factors.
Counterspell version of Decanter of Endless Water --- takes care of all the Milk he gets to drink (think magical Porta-Potty).
Body Outside Body (or similar) --- to leave behind an extra Santa, for all those succubi that stayed up late, to give the extra "milk" + "cookies" .
Red Cloth Armor with Immune to Water property --- to keep all the little kids pee-ing on him, as unproblematic as possible.
