Also called 'Father of Dragons', The Golden, Worm of Morgoth, The Great Worm.

Glaurung was the first dragon to come out of Angband, in year 256 of the First Age. He was only half-grown when he emerged, and this allowed the forces of Fingon to drive him back.

Glaurung next came forth in the Dagor Bragorlach, with Balrogs and Orcs in his train, and then again in the Nirnaeth Arnoediad, followed by Balrogs and wolves. In the Nirnaeth Arnoediad, he was wounded by the Dwarven Lord Azghâl, and driven back to Angband by heavily armoured dwarves.

He later led an assault for Morgoth on Nargothrond, where he first met Túrin and enchanted him so he could not move, even as his love Finduilas was herded past him by orcs.

He also put a spell on Nienor, Túrin's sister. She forgot everything, including her name. She and Túrin ended up marrying, not knowing they were brother and sister, and only when Glaurung removed his glamour from Nienor's eyes did she see the truth, and immediately killed herself in shame.

Túrin did have revenge though, he was the one to kill Glaurung, with his black sword, Gurthang.
Encyclopedia entry originally written by Hathaldir