Santa Claus
Exactly what you'd expect, he's an ancient force of good that has been helping the High Council for hundreds of years. An immortal wish-granter whose powers work in a similar way to the Blue Fairy and Fairy Godmother, he built a massive operation to grant wishes to the whole world once a year, and used the same technology to keep tabs on the Friends (they've all got a prominent position on the naughty list, natch). He was offered a spot on the High Council, but declined, wanting to keep his focus on Christmas Town, though he did once accept a brief assignment to visit Narnia and give the Pevensie sisters and their older brother items to help them in their war against the White Witch. Eventually, he decided to retire and pass on his powers (he didn't die, as it appeared in The Santa Clause, but rather simply disappeared leaving his suit behind), and Scott Calvin (who the original Santa had been keeping an eye on for a while) took on the mantle. It wasn't the smoothest transition, but he grew into the role and has recently been introduced to the High Council and picked up where his predecessor left off. The original Santa is enjoying retirement in Christmas Town with the Missus, though he still has command over Prep and Landing to help his successor in his job as well as spy on the Friends.