Maeglin the Traitor

"He resembled in face and form rather his kindred of the Noldor, but in mood and mind he was the son of his father. His words were few save in matters that touched him near, and then his voice had a power to move those that heard him and to overthrow those that withstood him." – The Silmarillion, Of Maeglin Maeglin was an Elf, the son of Eöl the Dark Elf and Aredhel daughter of Fingolfin. He lived in the First Age of Middle-earth and was a lord of Gondolin, chief of the House of the Mole. Maeglin revealed in front of Melkor the secrets of Gondolin in return of his life and for Idril - the wife of Tuor and the daughter of Turgon, King of Gondolin and last of the Noldor-princes. On Maeglin's advice Morgoth had his smiths and sorcerers construct iron monsters in the likeness of dragons, which might cross difficult terrain and harbour legions of orcs to transport them safely across the open plain of Tumladen. These monsters it is noted had never been seen before and never would be again untill the "Great End".