Emperor (The Panic Room)
The Emperor was an imperial ruler on the planet Arabia whose fear led to the construction of a panic room, a safehouse. However, the panic room was infiltrated by a panic creature that for years fed off the Emperor's fear. When the arrival of the TARDIS increased the Emperor's fear to a new high, the panic creature became fully manifest for a short while before the Eleventh Doctor, Amy Pond and Rory Williams convinced the Emperor that they were holograms and part of the panic room's defences. They created a chill-out zone which calmed the Emperor down and the panic creature was returned to its natural state. (COMIC: The Panic Room)