The U.S. Navy's Sea, Air and Land Teams (commonly known as Navy SEALs or SEALs) are the special operations branch of the United States Navy. They are mentioned in Call of Duty 4: Modern Warfare and are seen during the campaigns of Call of Duty: Modern Warfare 2 and Call of Duty: Black Ops II. The Navy SEALs have also been seen during the Call of Duty: Modern Warfare 3 reveal trailer. They are also a playable faction in Call of Duty: Modern Warfare 2's multiplayer. They are mentioned in Call of Duty: Advanced Warfare on the mission "Sentinel".