Bear Santa isn't so much a ghost as they are incorporeal while doing their wish granting thing because that makes more sense than a polar bear walking around the whole world. However if you wanna have some kind of Scrooge analogue for bears then you can go right ahead. Bonus points if you make them like the Three Little Bears but magic or some shit.

Religion has never really been as pervasive as it is in Earth culture due to Reasons but some of that stuff is still around so feel free to reference it in its obscure hipsterness.