Led by Sergeant Marcus Griggs, the unit served in Urzikstan in 2019 against Al-Qatala and were tasked with assisting Alex in apprehending The Wolf. With help from Alex, Demon Dogs were able to fight their way to the hospital where The Wolf was located, though three of their own had been captured and were planned to be executed. Alex and Grigg's manage to prevent the executions of three Marines and capture The Wolf before moving him to the American Embassy.
The name is likely based on the term Teufelshunden, which was a nickname given to the US Marines in World War I by Germans and later embraced by the Marines. It is more commonly translated as devil dogs but can also be translated as demon dogs.