Hellsteed
A Hellsteed is a type of Feral Chimera.
Overview

When the devil rides, he mounts a hellsteed. Also known as black unicorns, Diomedan chargers, night mares, and demon horses, hellsteeds have haunted humanity’s dreams for millennia. The masters of the fairy raed — the Wild Hunt — ride coal-black horses that can steal a person’s soul. The Four Horsemen bring about the Apocalypse while mounted on unearthly horses. Even the Headless Horseman of Sleepy Hollow sits astride a demon mount with smoldering hooves and fiery red eyes.
Wild hellsteeds are exceptionally rare encounters in the Near Dreaming, even for those souls brave enough to trespass near nightmare trods. On certain nights of the year, when the barriers between the worlds are thin, hellsteeds can appear to mortals, giving rise to legends of flesheating mares, flying stallions, unicorns, and horses with flaming manes.