Bernard (The Secret in Vault 13)

Bernard was the name given by the Thirteenth Doctor to a Mark VI combat mechanical who was sent by the Fleet to hunt her, Graham O'Brien, Ryan Sinclair and Yasmin Khan. After surrendering to it, the Doctor reprogrammed it using a virus that spread to all other Mark VI's, turning them into a peacekeeping force to step the aggression of the Fleet. (PROSE: The Secret in Vault 13)