The Harbingers or Thirdspace aliens are a mysterious and terrifying race of ancient and malevolent telepathic beings from an alternate dimension in Babylon 5.
Over a million years ago, the Vorlons built a jump gate to the Thirdspace dimension and soon discovered the aliens were powerful beyond their comprehension and older even than they were. They were driven by the primal need to devour entire universes. They are huge beings, are able to fly, can quickly regenerate damage to their bodies, and possess both telekinetic and telepathic powers. With their psionic powers they can create solid matter in the shape of chitin or stone. Telekinetically they can lift, move, or hurl objects the size of a midsize ground vehicle or smaller. Using their telepathic powers, the Harbingers influence the masses to serve their needs.