Santa Claus?

For those of you with fantasy-based AUs where Christmas is one of the holidays celebrated, does Santa Claus exist in that universe? If so, does he follow standard tradition - or is he someone a bit different? If you try to keep some sense of realism in that universe, is it hard for you to resolve the issue of him delivering presents around the world in one night? Even if we factor in time zones and him travelling westward, it still tends to heavily stretch willingness suspension of desbelief. Even if we factor in that he has the ability to slow down time for that one night, it's still an awful lot of work for one man to do.