In the west we know Santa Claus and Sinterklaas/Saint Nicholas. In the Alps we know Krampus who is an advisery to the winter figure. In the Pyrenees we find Olentzero taking the role. When we go east we find Miklavz and Mikulas and further east he turns into Ded Moroz. In Mongolia we find Chysh Khan.

These versions of the Winter Man all have companions, and they are all weird.
Belsnickel, Knecht Ruprecht, Black Pete, 6 Krampus like devils(Miklavz), an Angel & Imp duo,Schmutzli, Hans Trapp, etc
These are all related or based on each other in some way. To take famous Black Pete as an example, he is an almalgation of Knecht Ruprecht, Miklaviz's 6 krampusses, and Schmutzli viewed through the eyes of a victorian age childerens book writer.

There are more. Pretty much every place that has winter, has a version of this winter gift giving man and his companions. They are all very much alike in theme and it goes well beyond the anglosphere I think.

Where does this come from?
Originally I mean. It's obvious that the current versions are christianized versions of earlier things.
I have read some articles that thought it was based on Wodan/Odin. I'm not sure if that makes sense considering how widespread this thing is. It all feels as a tradition that is far older than Wodan, and we kept re-inventing it over many millenia and cultures.
Why we do it is obvious I think. Midwinter needs a fest to eat surplusses that would otherwise spoil, some in the community will need gifts of food to get through winter and various other such reasons.
But where does mr Winter Man and his companions come from?