true elf facts

Often Hador, and Galdor after him, had borne it in war; and the hearts of the host of Hithlum were uplifted when they saw it towering high amid the battle, and they cried: “Of more worth is the Dragon of Dor-lómin than the gold-worm of Angband!”

But in truth this helm had not been made for Men, but for Azaghâl Lord of Belegost, he who was slain by Glaurung in the Year of Lamentation. It was given by Azaghâl to Maedhros, as guerdon for the saving of his life and treasure, when Azaghâl was waylaid by Orcs upon the Dwarf-road in East Beleriand. Maedhros afterwards sent it as a gift to Fingon, with whom he often exchanged tokens of friendship, remembering how Fingon had driven Glaurung back to Angband. But in all Hithlum no head and shoulders were found stout enough to bear the dwarf-helm with ease, save those of Hador and his son Galdor. Fingon therefore gave it to Hador, when he received the lordship of Dor-lómin. By ill-fortune Galdor did not wear it when he defended Eithel Sirion, for the assault was sudden, and he ran barehead to the walls, and an orc-arrow pierced his eye. But Húrin did not wear the Dragon-helm with ease, and in any case he would not use it, for he said: “I would rather look on my foes with my true face.” Nonetheless he accounted the helm among the greatest heirlooms of his house.
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On the Dragon-helm of Dor-lómin

Unfinished Tales, J.R.R. Tolkien