At An Airport:

-Pack A Punch Inside Of Plane: Where the PAP Can Only Be Accessed By Moving The Jetway, Only Once A Round

-Jet Engine Trap, The Jet Sucks In All The Zombies

-M60 In The Game

-You Can Use The Conveyor Belts Like The Mine Cart On Shangri La

-Spawn In A Parking Lot

-Elevators

-Jet Train (Monorail)

-Different Concourses And Trains

-Resturaunts

-Huge Easter Egg

-Escalators

-Zombies Are Tourists

-Boss Is A Pilot

    In the city:

-pack-a-punch accesible without buying any doors

-trap would be the sewer hole(yeah i know weird idea xD)

-ability to give ammo to other players or even weapons (not by using hacker,it would be possible from start)

-the city would be largest zombie map yet with least doors to buy and most weapons to get 

-spawn on roof of grocery store and ability to jump down of it (results in red health with juggernog)

-this idea is just crazy:allowed to climb on roof of skyscrapper or tower and jump down from it with parachute or something and while in air allowed to shoot !!!

-upgrade improves: upgrade perk to get 2x original effect,upgrade every weapon including knifes 2x at pack a punch(second upgrade for more money idk thats up to treyarch how much xD)

-6 players lobby !!!!

-more zombies on the screen at same time (but more stupid and slower)

-more agressive dogs(and i wish they made some scary voices like raaaaaaaaaaaawr xD)

-dogs and monkeys(other than ascension ones) at the same time in "dogs round",also dogs could come randomly with zombies too like in der riese

-zombies would be ofc the people