Watchers in the Dark

The Watchers in the Dark are diminutive xenos who follow around the Dark Angels. No one knows what they look like, for they are covered in large green robes.

The Watchers were first known to the people of ancient Caliban as mysterious boogeymen who wandered the forests. In reality, they were a xenos race implied to be members of the Cabal dedicated to fighting Chaos (but really are little more than super-dicks who watch the galaxy burn, and even helped make it happen). They had been sent to watch over Caliban, which had been contaminated by Warp energy due to its proximity to the Eye of Terror, resulting in the Great Beasts who prowled the forests. Through a series of still unconfirmed events (which will likely be revealed in future Horus Heresy books; GW is nothing if not practiced at draining your wallet slowly) the Watchers in the Dark serve the Dark Angels as retainers and weapon bearers. They are also said to look over the comatose body of Lion El'Jonson, asleep in the Rock.