Carcharoth

Carcharoth, called Anfauglir the Jaws of Thirst by the Sindar, was the mightiest wolf ever to walk Middle-earth, bred and empowered by Morgoth to guard the gates of Angband. When Beren and Lúthien fled the fortress with a Silmaril, Carcharoth bit off Beren's hand and swallowed the jewel whole; its holy fire drove him into a ravaging madness across Beleriand. He was finally brought down at Doriath during the great Wolf-hunt, locked in mortal combat with the hound Huan. Mablung cut the Silmaril from his belly and set it in Beren’s living hand; from there the jewel went on by way of Thingol, Dior and Elwing to Eärendil, who bore it into the sky as a star.