Big Boss, more commonly known as Boss, Naked Snake (or simply just Snake), and to a much lesser extent, Jack. Big Boss was a CIA agent in the FOX unit during the Cold War, who participated in the Virtuous Missionand Operation: Snake Eater in 1964. During the Virtuous Mission, he was supposed to take a scientist named Nikolai Stephanovich Sokolov back to the United States, but failed thanks to the
intervention of his mentor, The Boss, her Cobra Unit, and Colonel Volgin. Because the Boss defected to the Soviet Union and the failure of the Virtuous Mission, the CIA gave Big Boss, known by his
old codename Naked Snake, a last chance to rescue Sokolov, and assigning him with new objectives: destroy the Shagohad, Colonel Volgin's nuclear weapon and kill Colonel Volgin and The Boss.
After defeating the Cobra Unit, destroying the Shagohad, and killing Colonel Volgin, he had one last objective - killing The Boss to prove the United States' innocence to the Soviet Union and averting nuclear war. Snake was then
given the title of "Big Boss" and the Medal of Honor by President Johnson. After killing the woman that taught him everything for ten years, he lost sight of the country he was fighting for, he turned his back on the United States and quit the FOX unit.
After abandoning the country that made him the soldier that he was. He got involved in several conflicts in many countries, including the San Hieronymo Takeover, and started FOXHOUND in 1971. He then left that unit to continue fighting and eventually
ended up in Columbia, where he met McDonnell "Kazuhira" Miller. They both started their own guerilla group, Militaires San Fronteires (Soldiers without Borders), which would eventually become known the infamous military group, "Outer Heaven": A
place for soldiers who answer to no government, country, or ideology.