War Doctor (Auton)

An Auton duplicate of the War Doctor was created during the Last Great Time War after allied with the Nestene Consciousness. Rassilon controlled the Auton to make use of the Doctor's inspirational reputation to Gallifreyan troops, but the Doctor bargained with the Nestene Consciousness to take control of his double, saving the lives of General Artarix's fleet.

When Rassilon berated him for this, the War Doctor before him was revealed as a second Auton duplicate serving to distract him while the real War Doctor escaped through the Cloisters. (PROSE: Decoy)