Creature (The Monsters of Coal Hill School)

Unnamed creatures were an unknown species of extra-terrestrial origins, who varied from skinny red to giant green and hairy blue. They copied Coal Hill School and teleported Jeff Delobel and Clara Oswald to teach them so that they could invade Earth. In the end, The Twelfth Doctor told them stories of Earth's guardian (being himself), which made them scared and called off the invasion. (COMIC: The Monsters of Coal Hill School)