Ocelot
07
Following the 2005 Shadow Moses Incident, Ocelot leaked the Metal Gear exercise data he acquired there to the black market, unleashing a swarm of Metal Gear derivatives throughout the world.
After receiving intelligence regarding the Marine Corps' new Metal Gear weapon, Metal Gear RAY (manned) in 2007, Ocelot plotted to steal it with the help of Russian Colonel Gurlukovich and his private army. After securing the disguised tanker carrying Metal Gear RAY, however, Ocelot betrayed Gurlukovich, stealing the Metal Gear prototype and disappearing to the sea bottom.
In 2009, Ocelot gave the manned Metal Gear RAY prototype he stole to Solidus Snake and participated in the subsequent takeover of the Big Shell, pretending to support Solidus Snake as he turned on the Patriots.
The entire Big Shell takeover, however, was just a dry run for the Patriots' S3 Project, with Ocelot in charge of collecting the data. Having learned that, Solidus activated Arsenal Gear, which had been disguised by the Big Shell, in order to make a final stand against the Patriots.
It was then that Ocelot began to act as if his body had been taken over by Liquid Snake's will, lingering within his right arm. Ocelot, playing the part of Liquid, announced that he was off to bury the Patriots, boarded Metal Gear RAY (manned), then disappeared into the sea.
Ocelot, with his right arm replaced with that of Liquid Snake, later has his body taken over by Liquid Snake's psyche. The fusion that resulted was Liquid Ocelot.