Guard (The Invasion of Time)
From Tardis Wiki, the free Doctor Who reference
A guard was a member of the Chancellery Guard on Gallifrey at the time of the Fourth Doctor's return to Gallifrey to claim the office of Lord President. While attempting to get into the Doctor's TARDIS, Commander Andred found he couldn't get into the ship without a key, and sent him to get the keys. When he returned, he found Andred had left, so he tried the keys until the door opened. K9 Mark I came out and either stunned or killed him. (TV: The Invasion of Time)
