The Ghosts are named after Modern Warfare 2 character Ghost and even have masks made after the mask Ghost wears. Riley the German shepherd is named after Ghost's real name (Simon Riley), and the honey badger assault rifle is named after an assault vehicle. The least selling game in the Call of Duty series.
John MacTavish better known as Soap is no exception. He is playable in the first and second Modern Warfare, appearing only as an NPC in Modern Warfare 3. Soap is responsible for killing Imran Zakhaev, as well as operating behind the scenes of World War III.