Sark is the secondary antagonist of the first film. He is played by David Warner.
Sark is chief lieutenant to the Master Control Program. He is created by ENCOM CEO Ed Dillinger, and shares Dillinger's voice and form. Sark oversaw the training of new programs kidnapped and brought to the Game Grid by the MCP, and was known to enter the games himself from time to time. He is destroyed by Tron near the end of the film. In the novelization, his program name is "SARK-ES1117821".
Read more about this topic: List Of Tron Characters, Tron