Lok

Governor Lok was the robotic governor of the Volag-Noc prison planet until Gurney used a hacking system to take over the jail. He locked up Locke. The Tenth Doctor and Martha Jones came to the prison, with the Doctor freeing Locke, who then rebelled against Gurney. Locke decided that all prisoners must be killed, but he was stopped by the Doctor. Locke was then deactivated and reprogrammed. (DW: The Infinite Quest)