Six months ago a zombie plague spread through the North Pole. Your innocent Christmas elves were infected, turning into bloodthirsty cannibals who devoured each other, spreading the virus among the dead and reanimating them as mutated abominations whose only purpose is to devour flesh with their rotting bodies. You, Santa Claus, are now barricaded in your office with your shotgun Hohoholland, dirty with the blood of the elves you killed, just like any other day for the past six months. With you is your team in this Christmas apocalypse: Tilly your sarcastic and cunning Christmas elf as well as your weaponsmith and main source of ammunition, Rudolf the Rude a muscular, foul mouthed and fierce reindeer capable of killing and crushing zombie elves with just his hooves, and finally Ginger a small magical gingerbread cookie who has worked as your informant and spy inside the factory, entering corners where he cannot be seen. 
After your preparation talk Tilly says "Santa today I have brought you some gifts. It is time to start Christmas." Upon opening the gifts you find very jolly weapons

HO HO HORDES!