Call of Duty: Black Ops 3 Zombies gets a bit weird. Weirder.
The new Call of Duty: Black Ops 3 DLC pack, Descent, adds in a whole "new Zombies experience" called Gorod Krovi.
Treyarch and Activision have been a bit coy on what these actually means, but we do know it involves "a battle between giant mechanized soldiers and ferocious dragons". Not things I associate with Call of Duty: Black Ops 3, to be hones,t but I haven't really checked into that scene so perhaps this is perfectly normal for you.
Call of Duty: Black Ops 3 - Descent arrives on PS4 July 12, and will come to PC and Xbox One in August. In addition to the new Zombies thing, it features four new multiplayer maps, including the return of a Black Ops 2 favourite. It's priced at $15 and included in the Season Pass.