A follower of Barahir, who remained faithful to his lord when Dorthonion was overrun by Morgoth in the Dagor Bragollach. Barahir and his last twelve companions were pursued by no less a hunter than Sauron, and at last their camp at Tarn Aeluin was betrayed. Nearly all of Barahir's band, including Dagnir and Barahir himself, were slain when the camp was attacked. Dagnir's name appears to mean 'bane': the same word appears in the inscription of Túrin's grave-marker, where he is called 'Dagnir Glaurunga' or 'Bane of Glaurung'.