The Harbingers are a Lovecraftian-like extra-dimensional race in the fictional universe of the Babylon 5 television series by Babylonian Productions Ltd.
The Harbingers (aka, Thirdspace Aliens) are a race from another universe. Whom are very large compared to humans with a form that is a sort of hybrid between a cephalopod and spider with multiple glowing eyes on a large bulbous head that is on a fleshy structure with multiple dexterous appendages. Within the folds of the fleshy structure is a pair of snapping jaws. Harbingers are telepathic, can instantly move from location to location, and create solid appendages used as projectiles.
They have ships that are partly organic that have shell like structures, veined tentacular appendages, sections that seem to be made of smoke and crackling energy, and parts which appear to be disconnected from the ship. Their cities have 5 mile twisted towers that are surrounded by squat uneven buildings and floating structures. It's a species which considers itself the only one that deserves to exist in the multiverse and have destroyed thousands of species in their home universe, and have spread their campaign to other realities. Much as the Drakh are the agents of the Shadows, the Hand are the agents of the Harbingers.