 In the reign of Fachtna Fáthach, Ross was killed in the Battle of Lough Foyle, and Fergus was made king of Ulster again.In the "Saga of Fergus mac Léti", he encounters water-sprites called "lúchorpáin" or "little bodies"; this is thought to be the earliest known references to leprechauns.The creatures try to drag Fergus into the sea while he is asleep, but the cold water wakes him and he seizes them.