Utility stand-in
From Tardis Wiki, the free Doctor Who reference
A utility stand-in serves to match an actor's general appearance, to aid with lighting and camera setup whist the actor is not present.
As of 2017[update], Ian William George was the only credited utility stand-in for Doctor Who. He received credit for this role in The Day of the Doctor and The Time of the Doctor. Previously, he was Matt Smith's "voice double" in The Almost People.
