Whether it’s for camo challenges or the main story missions, you will eventually need to get Toxic Damage Kills in Modern Warfare 3 Zombies. Unlike other damage types, Toxic is never really described by name in the menus, but I can easily help you get the right items.
MW3 Zombies: How to Get Toxic Damage Kills
You can get Toxic Damage Kills by using the Brain Rot Ammo Mod on any of your weapons or by using the Experimental Gas tactical equipment. Overall, the best way to get these challenges out of the way is to use the ammo mod. Most of your shots will do passive Toxic Damage with Brain Rot, so you won’t need much effort.
The only setback is actually finding an ammo mod. However, you can find a ton of them in Aether Caches around Urzikstan, or if you’re lucky enough, you can use the Schematic for the ammo type to craft a free one. Either way, the camo challenges will likely require you to have on the Brain Rot Ammo Mod for the kills to count.
Experimental Gas is the second method for getting Toxic Damage Kills in MW3 Zombies. Much like Tear Gas from Multiplayer, this tactical will spread a ton of gas in a condensed area that deals damage over time to zombies or mercenaries. I like to dish out small amounts of damage with my primary weapon and let the gas do the rest of the work.
Of course, you can always use both the Experimental Gas and the Brain Rot Ammo Mod if you want to rack up as many Toxic Damage Kills as you can. Head to an extraction, round up the zombies, and watch the toxic effect melt them away.
For another damage type, learn how you can get Cryo Freeze Ammo in MW3 Zombies.