The Hound of Ulster and the Warp-Spasm

Cu Chulainn is the supreme hero of the Ulster Cycle, and the greatest of the Old Irish sagas, the Tain Bo Cuailnge (Cattle Raid of Cooley), turns on him. A son of the god Lugh, born Setanta, he earns his name, "the Hound of Culann", as a boy by killing the smith Culann's ferocious guard-dog and pledging to take its place until a replacement is reared. His defining feature is the riastrad or warp-spasm, a monstrous battle-fury that contorts his body into an unrecognizable engine of destruction.

In the Tain he single-handedly holds the province of Ulster against the invading army of Queen Medb of Connacht, fighting a series of single combats at a ford while the men of Ulster lie helpless under a curse. His life follows the pattern of the doomed hero: he chooses, knowingly, a short life of undying fame over a long and obscure one, and dies young, binding himself upright to a standing stone so that he might meet death on his feet. He remains a potent emblem of Irish identity, claimed in the modern era by nationalists and revivalists alike.