Elemental Shade

The Elemental Shades were a type of living shadows. In the 1970s, an Elemental Shade escaped the Howling Halls and was tracked by the Tenth Doctor to the home of Elton Pope and his mother. It managed to kill Elton's mother before the Doctor could stop it. (TV: Love & Monsters)

BEHIND THE SCENES

 * They are remarkably similar to the Vashta Nerada, who are also described as being shadow like creatures that kill humans.