Ravenloft II: The House on Gryphon Hill
Legends around the Mordent region speak of a terrible specter that haunts the moors and lonesome roads at night; a headless horseman said to herald death to whoever sees it. Though the stories of who or what this phantom is vary, it is universally known by its title: the Dullahan.
How it came to be is contested. Some stories say the Dullahan was once a proud defender of peace and justice who died a tragic death, cursed by black magics to wander the world in undeath and spread misery; others claim the Dullahan was a highwayman who was beheaded for his crimes, the vengeful ghost indiscriminately killing all it comes across; while still others say the Dullahan isn’t a spirit at all, but a malicious fey that takes on the horrid guise of a headless horseman. Regardless, they all agree that the Dullahan should be avoided at all costs.
The Dullahan is commonly described as a figure swathed in a black cloak that seems to billow as if it were alive, sitting astride a phantom steed with burning red eyes (in some legends, the horse itself is also headless, the severed head of the beast floating just a few inches above the neck). The Dullahan carries its disembodied head, whose moldering skin barely clings to the strangely-glowing skull, in one hand and a ghastly whip made from a human spine in the other. It is said the Dullahan can ride like the wind, becoming as insubstantial as a shadow. Legends further tell that when the Dullahan holds his head aloft like some grisly lantern and calls a name, the person hearing it will die shortly thereafter; the Dullahan does this to steal souls.
The only thing said to ward off the Dullahan is the presence of gold. Travelers are advised to carry their coin with them, for the Dullahan will not get near anything made of gold.