Call of Duty: Modern Warfare 3 Zombies features several different damage types you can use to kill enemies on the infected Urzikstan map. While you’re not required to use any of these types of damage, you do need to use Toxic Damage for certain challenges in MW3 Zombies.
Most forms of damage are required to be used for different challenges in Zombies, but Toxic Damage is arguably the most confusing out of the bunch. Luckily, dealing Toxic Damage is not as difficult as it might initially seem. To see exactly how to kill enemies with Toxic Damage in MW3 Zombies, keep reading the guide below.
Dealing Toxic Damage in MW3 Zombies
For starters, you can technically deal Toxic Damage in a couple of different ways. However, if you’re going for a weapon camo challenge, such as one for the Rival-9 SMG, you can only use one of those methods.
The two methods of dealing Toxic Damage in Zombies is using the Brain Rot Ammo Mod and the Experimental Gas tactical grenade. The Experimental Gas grenade can be equipped on your loadout before you drop into a match of Zombies, but you only gain access to one of these grenades before you run out. This means you need to resupply the grenade throughout the course of a match if you want more of them.
As for the Brain Rot Ammo Mod, this can either be looted as an Acquisition or Schematic. If you find the Ammo Mod as an Acquisition, you can either stow it in your Rucksack or equip it onto your weapon. If you find it as a Schematic, you can add it to your Rucksack, successfully exfil, and then you’ll be able to craft it for an unlimited supply of the Ammo Mod.
Related: What are Elite Zombies in MW3?
Brain Rot is an Ammo Mod that allows you to randomly turn a zombie into a friendly, making it attack other zombies for a brief time before it kills itself. If you’re going for a weapon camo challenge, this is the only way you can deal Toxic Damage. If you don’t use Brain Rot, your kills won’t count, even if you’re using the Experimental Gas grenade to kill zombies.
So, depending on what challenge you’re trying to complete, you can either use both forms of Toxic Damage or only one.