Cuchulainn

Celtic mythology his first name was Sentana, and after killing Culann the blacksmith's dog, he took the name of Cuchulainn and functioned as the smith's guard dog for a time. He died in battle on Samhain eve and while dying, the Morrigan in the shape of three crows, sat on his shoulders.

A legendary Celtic warrior of the kingdom of Ulster. According to legend, he was given the ability to fall into a blood rage during battle by the goddess Morrigan, in which he would grow in size and strength, his hair would stand on end with drops of blood flying from it and a halo of light forming around his head.

The city of Ulster had a curse placed on it by a sorcerer many years before Cuchulainn's time. The basics of this curse were that whenever an enemy attacked, every man who was old enough to grow a beard would have horrible birthing pains for nine days. The distinct advantage that Cuchulainn gave Ulster was that for all his size and strength, he was never able to grow a beard. So it came to pass that one year, when a particularly large army attacked, Cuchulainn was the only soldier able to fight. He stood in a narrow mountain pass as the opposing army advanced, and took off their heads, one by one, killing more than a thousand men in one day.

His death was the result of a geas placed on him during his mother's pregnancy with him: He could never be awoken from his sleep by another person, or else great misfortune would befall him. The violation of this ban on the eve of a great battle, combined with the use of three magical arrows and an enemy seer's prophecy led to his death.

It's also said that during his blood rage, Cuchulainn's erect member could cave in the side of a chariot and kill the rider.