Known as “The Lonely Assassins”, the Weeping Angels are quantum-locked alien killers, as old as the universe itself. Little is known of their origins or culture. When observed, they freeze like stone, but in the blink of an eye they can move vast distances. The touch of an Angel hurls their victim back in time – allowing the Angel to feast on the energy of their unlived days. Initially, the Tenth Doctor encountered four Angels, who sent him back to 1969. He left clues for Sally Sparrow to find and help trap them – releasing him and the TARDIS. Later encounters have seen a whole mausoleum of statues, tiny cherubs and even the Statue of Liberty transformed into Weeping Angels. Both Amy and Rory were trapped by a Weeping Angel, when it sent them back to 1938 to live out their lives together. In the 51st Century, the Doctor trapped the Angels in a crack in time, erasing them from history.