Long before Sleepy Hollow, Ireland had a headless horseman, and he was far worse. The name Dullahan is often explained as 'dark man'; the exact origin is uncertain. What the tellings agree on is the figure: a headless rider who speaks one name. He rides a black horse through the countryside at night. He has no head on his neck. He carries it under his arm or holds it high, and it is described as having a mouldy, cheese-pale skin, eyes that dart about constantly, and a wide grin that reaches from ear to ear.
In his other hand he holds a whip. It is made from a human spine.
The Dullahan is a messenger of death. When he rides, it is because somebody is about to die, and he is on his way to collect them. When he reaches the right place, he stops his horse, lifts his head, and speaks a single word: the name of the person whose time has come. That person dies at that moment. The Dullahan never needs to say anything else.
Nothing stops his ride. The old tellings say that every locked gate flies open at his approach, and no fence or wall can hold him back. Some describe him driving a black coach — the cóiste bodhar, the silent coach — drawn by headless horses, its wheels spinning so fast they set the hedgerows alight. Some say that if you are foolish enough to watch him pass, he will throw a basin of blood in your face, marking you as a future passenger — or simply lash out your eye with his whip.
There is one thing that frightens him: gold. Even a small piece — a gold pin, a coin — thrown in his path will make him turn aside. It is not clear why. It may be connected to an old belief that gold, like iron, is a metal the otherworld cannot abide. Whatever the reason, it is the one defence the tellings agree on.
Some folklorists have connected the Dullahan with Crom Dubh, an ancient god said to have been honoured with human sacrifice, including beheading; when the old worship faded, perhaps the god became a headless spirit still looking for the dead. The truth is unknown, and the tellings don't need to explain it. He shares a road with other death-bringers of the Celtic world — the Breton Ankou with his creaking cart, the Irish banshee with her keening, and the Welsh Gwyn ap Nudd riding with the hounds of Annwn.
Wear the Dullahan and you wear the darkest ride in Irish folklore — the one rider you do not want stopping at your door.