In zombies you have perks which are drinks that give the player special abilities, on normal maps you can have 4 perks. There are exeptions to the 4 perks rule like the gobblegum Perk-a-holic (Gobblegum that gives you all the perks available on the map) and on big maps like Origins you get 8 perks.

all the perks currently available in cod zombies: