Sometimes with the epithet ‘of the Terrible Hand’. Grandson of Fionn mac Cumhaill and known for laziness, he does not appear in Fenian literature until the 12th century. In one early text he is described as the son of Lugaid Lága, but he is usually seen as the son of Fionn's daughter Lugach. Trained by Mongfhind (2), he initially shows little prowess and gets on poorly with fellow students. He later shows great strength and musicianship. Fionn's advice to him is cited widely in Fenian literature: never to meddle with a fool, and to be gentle with women, servants, poets, and the common people. He is thought to have planted the stones of Ireland in memory of his first love, Tuadh. In later texts Mac Lughach is one of Fionn's closest compatriots.