Yule
Yule is an old word for Christmas. Very Old.
In fact, in an example of what religion scholars would call "syncretism," the word derives from the name of the old Norse winter holiday Jol—a celebration that was, in a sense, 'absorbed' by Christmas as the native religions of Europe became Christianized over the course of centuries.
The "Yule log" is likely a vestige of this ancient pagan holiday. The "Yule goat" and "Yule boar" did not make the cut.