Robot Doctor
The "Robot Dr Who" was created by the Daleks to "infiltrate and kill" the Doctor and his companions.
Profile
Vicki happened to stow away on-board the Daleks' DARDIS when the Robot Doctor was created. She alerted the real Doctor, Ian and Barbara to its existence. When the whole party met it, the timing of the meeting meant that Ian, Barbara and Vicki couldn't tell which was the real Doctor and which was the Robot, and in the confusion Ian attacked the real Doctor. The Robot kept up the pretense and tried to persuade Ian to kill the real Doctor by smashing his head with a rock; before Ian could do so, the Robot made a fatal mistake and revealed that its knowledge of the Doctor's travelling was outdated by calling Vicki "Susan." Barbara immediately realised that it was in fact the Robot and prevented Ian from killing the real Doctor. The Robot was subsequently destroyed in the fight with the Doctor and his companions. (DW: The Chase)
Behind the Scenes
Edmund Warwick did not resemble his "exact duplicate", played by William Hartnell, making the impersonation not work very well on camera.
