I was recently wondering about the origins of Santa Claus and the stories of flying reindeers, Rudolph with the red nose, the fact that Santa came from the north pole and used to go to people's houses through the chimney to leave gifts. Where does that come from? Well I did a little research and it seems that the link might be magic mushrooms (Amanita muscaria).
These mushrooms, which typically grow under coniferous trees, are apparently sought after by reindeers who love to eat them. Also, Shamans in Siberia used to collect them, dry them on trees and give them as gifts during the winter solstice. The more I looked into it, the more links there seemed to be. Quite a fascinating find, and what inspired this drawing.