How do you get bo2 pap zombies camo?

To unlock the Pack-a-Punch (PaP) camo in Call of Duty: Black Ops 2 Zombies, you need to upgrade your weapons at the Pack-a-Punch machine. To access the machine, you must first complete specific tasks depending on the map, such as turning on power or opening certain doors. Once you have upgraded your weapon, it will receive a unique camo, signifying that it has been Pack-a-Punched. Keep playing to earn additional camos by upgrading more weapons.