The Master Control Program (usually shortened to MCP) is the main antagonist of Winnie the Pooh meets Tron. It was a computer program created by Ed Dillinger that ruled inside ENCOM's mainframe computer to overview the game system, but rebelled himself and decided to get rid of the humans (users, as he usually refers to them). During the rule of the MCP, many programs were enslaved and pitted against the program's henchmen, led by Sark. He tried to absorb the tower guardians and take over the system, but the MCP was de-rezzed by Tron and Flynn.
The MCP's Earth form: Cyber Shredder