The Cybermen

 The Cybermen were originally humans, and the scientists of their home planet Mondas perfected cybernetics. They initially replaced only their limbs with metal and plastic, but they gradually progressed to the nervous system and finally the brain. The end product was the Cyberman, who were huge metal giants, devoid of emotion, only acted on logic, immensely strong and intent on conquest. Their great weakness is that gold is fatal to them.

The Cybermen started like the picture at the top of the page, and as they progressed, they developed better limbs and by the picture at the bottom, they had no traces of a human.

The Cybermen created small, mechanical rat-like creatures called Cybermats. They are capable of injecting a deadly poison into whoever they touch. The Cybermen also created the Cyber Androids which were deadly black androids controlled by the Cybermen. They massacred an archaeological survey team who had came too close to a hidden bomb intended to destroy the Earth.    

The picture on the left shows the Cybermen in the Death Zone on Gallifrey.

The Cybermen were in Tenth Planet, The Moonbase, The Tomb of The Cybermen, The Wheel in Space, The Invasion, Revenge of The Cybermen, Earthshock, The Five Doctors, Attack of The Cybermen, Silver Nemesis