Poison Gas Soldiers first appeared in the Strike led by Big Mouse. Their objective was to poison the whole city, and to neutralize the civilians in Panama Canal. Most of these soldiers were defeated by Ivan. When Ivan arrived at the Church, Big Mouse and a group of Poison Gas Soldiers waited for him. Big Mouse held a Speech about Ivan's betrayal and when he finished he and the Poison Gas Soldiers attacked Ivan.
A few Poison Gas Soldiers appeared in the flight Center, trying to defend it but with no success.
Some Poison Gas Soldiers were present during the attack on Mladshiy Braat island and defended the ground.
Poison Gas Soldiers are equipped and skilled with Knifes and either use a Bizon RIS (only in Mission 2) or a M-21 with attached flamethrower. They are Chemical Warfare Experts that use Poison Gas with no remorse.
This Unit is also responsible for creating the Chimera Virus.
- Although their usual firearm are either a Bizon RIS or a M-21, Several Poison Gas Soldiers were seen using different weapons during Big Mouse's Boss fight. To the weapons count:AK-12, Kbkm wz. 2003 and RPGs.
- They apear as Holograms in Hattie's. The player can test weapons on them without them attacking back.
- They wear Gas Masks only in Mission 2.