My personal opinion is that Santa Claus may represent the survival of one or more Pagan deities and archetypes. He has his reindeer in the same way that the Gods Cernunnos of the Celts and Freyr of the Norse-Germanic peoples were associated with stags and other horned creatures. The Norse God Odin was called "Jölföðr" which means Yule-Father and parallels the name Father Christmas a.k.a. Santa Claus. Merlin rode a reindeer as he returned from Scotland and sometimes is represented in the shape of a stag. Santa travels across the sky as did Odin and apparently Cernunnos as well. Santa's helpers are elves and Freyr was considered to be the Lord of the Light Elves and his stronghold in Asgard is Alfheim(Elf-home).
Santa-like archetypal figures are often associated with shamanic practices in ancient societies, so I'd imagine that calling Santa Claus a shaman isn't too far off the mark.
Blessed Be,
Lord Badger