The dullahan is a headless rider, usually on a black horse who carries their own head under one arm. The head's eyes are small, black, and constantly dart about like flies, while the mouth is constantly in a hideous grin that touches both sides of the head. The flesh of the head is said to have the color and consistency of moldy cheese. The dullahan uses the spine of a human corpse for a whip, and their wagon is adorned with funeral 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.
There is no way to bar the road against a dullahan—all locks and gates open to them when they approach. They do not appreciate being watched while on their errands, throwing a basin of blood on those who dare to do so (often a mark that they are among the next to die), or even lashing out the watchers' eyes with their whips. They are frightened of gold, and even a single gold pin can drive a dullahan away.