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 Lok. The Tenth Doctor and Martha Jones came to the prison. The Doctor freed Lok, who then led a rebellion against Gurney. Lok decided that all prisoners must be killed, but he was stopped by the Doctor. Lok was then deactivated and reprogrammed. (DW: The Infinite Quest)