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How to deal toxic damage kills in MW3 Zombies

Show those zombies who's boss.

Modern Warfare 3 Zombies
Image credit: Activision

Players that want fancy new camos for their weapons in Modern Warfare 3 Zombies will need to complete some challenges to do so, and one such challenge to unlock the Blister Digital TAQ-56 camo involves dishing out toxic damage kills.

Getting yourself 250 kills using toxic damage is no easy feat initially, but once you know exactly what you need to do to get those toxic damage kills, you’ll find unlocking your shiny new camo a breeze. Here’s how to deal toxic damage in MW3 Zombies.

How to deal toxic damage in MW3 Zombies

There are two ways in which players can attempt to get toxic damage kills in MW3 Zombies; the first is using Experimental Gas, while the second involves using the Brain Rot Ammo Mod.

When you arrange your loadout to enter a new MW3 Zombies match, you’ll be able to choose a tactical piece of gear to take with you. At first, you’ll only be able to take Stun Grenades, but if you manage to reach Level 18 and complete five daily challenges, you’ll unlock the ability to take Experimental Gas with you instead.

The player picks up some Experimental Gas from a bed in a building in MW3 Zombies
Experimental Gas can be found easily throughout a match. | Image credit: Activision/VG247

Alternatively, Experimental Gas is a common item that you’ll typically find on multiple occasions throughout a match, too. It can be dropped by enemies, found in Loot Caches, and found in various other lootable spots, too. That said, it is randomly spawned.

When Experimental Gas is thrown at a group of enemies, they’ll be temporarily slowed and may receive a small amount of damage. If you kill zombies within the gas while they are slowed by it, it will count as a toxic damage kill. Voila. Now to find enough Experimental Gas to take on 250 zombies…

The player receives the Brain Rot Ammo Mod from a Reward Rift in MW3 Zombies
Image credit: Activision/VG247

On the other hand, there’s the Brain Rot Ammo Mod. This item, when found, will let you directly deal toxic damage to enemies by shooting them. The Mod is a lot more difficult to find than Experimental Gas, with it being a random drop you might get from Aether Caches (often found in Infested Strongholds) and Reward Rifts (from completing Contracts.)

The player looks at a lootable aether cache covered in crystals in MW3 Zombies
Look out for Aether Caches. | Image credit: Activision/VG247

You may also be in with a chance of randomly finding the Brain Rot Ammo Mod schematics.

The player looks at the Brain Rot Ammo Mod in schematics crafting in MW3 Zombies
If you find the relevant schematic, you can also craft the Brain Ammo Rot Mod. | Image credit: Activision/VG247

If you’re lucky and manage to exfil with the schematics in your possession, you’ll then be able to craft the ammo to take into a match with you, much like the Cryo Freeze Ammo Mod. It’s worth noting that all crafted schematics have a cooldown before you can craft them again, though.

For more on MW3 Zombies, check out how to get a Large Rucksack so you can bring home as much loot as possible, what we think the best guns to play around with are, and how to craft schematics if you’re stuck.

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Call of Duty: Modern Warfare 3 (2023)

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About the Author
Kelsey Raynor avatar

Kelsey Raynor

Guides Writer

Kelsey's passion for gaming began with Resident Evil, and it's been rather difficult to get them to shut up about horror games since. When they're not scoping out new scares or commiserating the cancellation of Silent Hills, they can often be found fawning over cute Pokémon and Kirby, or being very average at FPS games. They've been in games media for 3 years.