The Mystery Box can be found on all TuckerZombie maps. It usally contains an item like a key that you can use to find things, but it sometimes contains an ally as well.
How it WorksEdit
TuckerZombies: Deep S**tEdit
In this map the Mystery Box can give you one of four items/allies. It can give you a key, a shovel, (the purpose of which is still unknown) a Juggernaut, (ally) or Mario. (the one from Nintendo)
In this map the Mystery Box will give you a key. Each key will open a gate with a soldier behind it that you can ally. Each gate is different, and each one has a different soldier behind it. Depending on what key pops out is what soldier you'll be able to ally.
~The Mystery Box holds a different item each time you play. ~The Mystery Box appeared in CoD as a box that gave you a random weapon when you opened it.