Ferdiad, was a warrior of Connacht in Irish Mythology. In the Táin Bó Cuailnge (The Brown Bull of Cooley) Ferdia finds himself on opposite sides to his best friend and foster-brother Cúchulainn, with whom he had trained in arms under the renowned warrior woman Scathach. He and Cúchulainn are equal in all martial feats, with two exceptions: the Gae Bulg, a barbed spear which Scathach has taught only Cúchulainn to use; and Ferdiad’s horny skin, which no weapon can pierce.
For days they battle it out, fighting by day and tending to each others wounds by night. During the battle for the Brown Bull of Cooley, Cúchulainn throws a light spear at Ferdiad’s chest, causing him to raise his shield, and then picks up the Gáe Bolga between his toes and thrusts it through his chest and piercing his heart and impailing him to the river bed floor, killing him. The ford where he died is named Áth Fhirdiad (Ferdiad’s ford, modern Baile Átha Fhirdhia or Ardee, Co Louth) after him.