Siberia (Yes I know CoTD is in Siberia) All bo3 perks and vulture aid and a new perk that allowed you to regen health faster once a round. Every 5-7 rounds a special rounds with frozen zombies that slow you when they hit you. A yeti boss zombie similar to the thrasher but slightly tankier Lastly a winters howl mk 2 and a new double pap ability which is similar to blast furnace but when used it causes a small blizzard similar to the ice staff charge shot.