Koledo: an old Slavic deity that can be seen in two ways – as a winter spirit and as a god. Festivals dedicated to Koledo took place in the winter, and the most important one was Koljada that coincided with the date of the winter solstice.
Customs related to this holiday survived into Christianity, and some authors consider that Christianity took this holiday over and transformed it into Christmas. In Bulgaria Christmas is still called Koleda, and the greeting used on this day is “merry Koleda”.
Nice picture! :3