The sacrifice of gods and sacred kings was a sacred rite meant to bring life back to the land and ensure a bountiful harvest in the fall. It was a rite of renewal and hope.
As I noted at the top, this post in no way covers the entirety of Santa-related mythology. This is a big story and it has more branches than I could ever hope to cover. But I wanted to give y'all an idea of just how expansive and old this legend is.
Mother Holle is a little like Baba Yaga in that she has a fearsome visage and she may offer help or hindrance, depending on how she feels about you. Unlike Baba Yaga, however, Mother Holle's motivations are much simpler: she really just wants someone to fluff her bed every morning.
Much like Santa Claus, Perchta was believed to visit houses between Christmas and Epiphany in search of who had been good or bad. If you had been a good child--worked hard and behaved yourself--you might find a silver coin in your shoe. If you hadn't, well...
It was Hekate and her torch that assisted Demeter in her search for Persephone, and it is Hekate who leads Persephone back and forth on her yearly journey between life and death. Hekate's transformation into the patron of witches arose out of this chthonic and nocturnal nature and she became heavily associated with herb-lore and the use of poisonous plants. It was written that Hekate was the patron of the witch Medea, which helped to further her reputation as the Goddess of Witches.
At its root, the hunt is believed to serve as a symbol of the wildness and chaos of nature. It reminds us of nature's inherent darkness and that we should remember to be afraid of the black night because dangers abound for those who are careless enough to be caught out when the riders come to call.