In Irish folklore, what headless horseman is considered a fairy?

In Irish folklore, the headless horseman considered a fairy is the Dullahan.

The Dullahan is usually portrayed riding a black horse while carrying his own severed head. In other versions, he drives the cóiste bodhar, or “deaf” or “silent coach,” a death coach whose appearance foretells death or misfortune.

The figure is linked with the Irish term dúlachán, often interpreted as a dark, fierce, or malicious being. The Dullahan is commonly described as an unseelie, or dangerous, fairy rather than a benevolent modern fantasy fairy. Gold is sometimes said to repel him.

The Dullahan is not identical to every headless horseman in folklore. Washington Irving’s Headless Horseman belongs to the 1820 American story “The Legend of Sleepy Hollow,” while the Irish Dullahan’s best-known literary collection is Thomas Crofton Croker’s Fairy Legends and Traditions of the South of Ireland, published in 1828. Scholars also note that evidence for the figure in older native Irish oral tradition is limited.