Reynart (android)
From Tardis Wiki, the free Doctor Who reference
An android duplicate of Prince Reynart was made to take his place at his coronation because it was feared that Reynart would be killed by Grendel if he showed up. The android was repaired and improved by the Fourth Doctor. After the coronation, Grendel, aware that the new "king" was an android, destroyed it. (TV: The Androids of Tara)