In Call of Duty: Modern Warfare 3, the Reaper is seen during the Campaign mission, Persona Non Grata, where it is being used by the Inner Circle to attack Loyalist forces in India. Another appearance is in the Special-Ops DLC mission- "Kill Switch" as Ozone uses it to clear waves of enemies approaching Sandman as he is clearing an objective. The Reaper also appears in Multiplayer as the ReaperStrike Chain.
The Reaper returns in Call of Duty: Modern Warfare II, Call of Duty: Warzone 2.0 and Call of Duty: Warzone Mobile as the UAV.
In Call of Duty: Modern Warfare III, the Reaper once again appears as the UAV, as well as the Missile Drone and Loitering Munition.