Glaurung is described as the father of dragons in J.R.R. Tolkien’s The Silmarillion. He is the first of the great dragons created by Morgoth in the First Age.
Glaurung first appears from Angband during the Battle of Sudden Flame, before he has fully developed his wings. He later becomes a central enemy in the story of Túrin Turambar, using his strength and hypnotic speech to cause devastation.
Glaurung is distinct from Smaug, the dragon in The Hobbit, and Ancalagon the Black, the largest winged dragon associated with the War of Wrath. The title “father of dragons” refers specifically to Glaurung’s place in Tolkien’s mythology.