Scobie (Auton)
From Tardis Wiki, the free Doctor Who reference
This Auton duplicate of General Scobie was made to take the real Scobie's place and command the army. He retrieved the final Nestene meteorite control unit from UNIT before returning it to Channing, then took a squad of men to arrest the Brigadier's UNIT men when they raided Auto Plastics. However, the Third Doctor uncovered this Scobie as an imposter by deactivating him, revealing that he was just a plastic dummy. (TV: Spearhead from Space)