|First Appearance:||Mother Russia|
|Portrayed by:||Tony Millan|
The Interrogator or The Shape Thief was a creature who had the power to copy bodies and disguise himself. He landed on Earth in Russia in 1812 during a battle between the French and the Russians. He copied Semian Borisovitch Starzoff's body, and killed and hid the real person. Using his powers then, he copied the Doctor and tried informing Napoleon Bonaparte of an easier route into Moscow.
He soon came to the Frenchman's side and was trusted. The real Doctor, however, thwarted his plan and persuaded Napoleon that he was the real Doctor. In the end, while investigating Steven Taylor, the creature was killed because of his own misery. (Mother Russia)