Chemo

Chemo is a Task Force 141 operative that appears in Call of Duty: Modern Warfare 2 

Biography
Chemo is first seen in the campaign mission "The Hornet's Nest", with Captain MacTavish, Ghost, Roach, and Rocket running through the favela to the evacuation site. He is later seen in "The Gulag" and will randomly appear throughout the campaign. Depending on the player's actions, Chemo can eventually be killed.

Trivia

 * He and Rocket are always the first two randomized soldiers in "The Hornet's Nest".
 * Chemo and Rocket will both always be replaced by another Task Force 141 soldier (if they die) up until the player reaches the market.
 * Even if Chemo dies in "The Hornets Nest", he still might show up in other levels as a randomly-generated character.
 * Chemo will always spawn with an SMG.
 * There is a Chemo in Call of Duty: Modern Warfare 3 and spawns as a Delta Force operative in Survival Mode.
 * Despite the player's actions, either he or Rocket will die in The Hornet's Nest.