My first xmas in this game, and the event looks pretty decent. There are essentially 4 parts to it and plenty of grinding.
Here you can kill lazy reindeer who neglect their training and gather Snow Crystals, various Presents, and Elifedora. All of these can be exchanged for xmas-themed limited items.
Santa offers Santa suit pieces, holding and back items, and Santa sleigh cart for crystals and Elifedora. To get the sleigh cart, you must wear the Santa suit on your avatar and talk to Santa again since this time an option for Rudolph Suit and Back items will open up. After you get and equip the Rudolph Suit, you will be allowed to purchase sleigh cart parts.
Grouchy reindeer Bob offers black Santa suit for stolen present boxes. Run around all of the maps and click on ground present boxes to steal them.
And Presents themselves contain Christmas Trees and Snowballs to be used for fun.