Omegal is a "Death Prophet" said to appear before those on the brink of shoving off this mortal coil. All who see him quiver in fear of his morbid presence. Will they be taken by illness? An accident? Perhaps a natural disaster? None of these is correct. Rather, Omegal himself kills them right where they stand. After all, he hates being espied by human eyes. Perhaps "Death Prophet" is a misnomer. In truth, he is the "Deathbringer."
The Irish dullahan (also Gan Ceann, meaning "without a head" in Irish) is a type of unseelie (darkly-inclined) fairy. The dullahan is a headless rider, usually on a black horse who carries his or her own head under one arm. The dullahan uses the spine of a human corpse for a whip, and their wagon is adorned with funereal objects (e.g. candles in skulls to light the way, the spokes of the wheels are made from thigh bones, the wagon's covering made from a worm-chewed pall) or dried human skin. When the dullahan stops riding, that is where a person is due to die. The dullahan calls out their name, at which point they immediately perish.
Artwork by Dmitry Klyushkin aka delor.