Jaws of Thirst

Carcharoth was a great wolf raised by Morgoth to guard the Doors of Angband, but when Beren and Lúthien approached the stronghold of the Dark Lord, Lúthien sent the Wolf into a deep enchanted sleep. Thus the two were able to steal into Angband and recover one of the Silmarils from Morgoth's Iron Crown, but returning through the Doors they found Carcharoth once again awake. Lúthien no longer had the strength to cast the Wolf into sleep, and so Beren attempted to daunt him with the holy Jewel.

Beren's gamble failed: Carcharoth bit off his hand at the wrist, swallowing it along with the Silmaril it held. Long ago Varda had hallowed the Jewels to consume evil flesh with burning fire, and so the great Wolf was filled with tormenting pain. Maddened with agony he fled from Angband, and from this time he was known by the Elvish name Anfauglir, translated as the 'Jaws of Thirst'. He made as way as far south as Doriath, leaving a trail of destruction as he sought to quench the burning of the Silmaril. When he reached a fall on the river Esgalduin he drank deeply, and there he was found by a band of hunters. These were led by King Thingol, who had set out on the Hunting of the Wolf when Beren and Lúthien had returned and told their story. The hunters succeeded in defeating the Jaws of Thirst by the river, but Beren too lost his life in that battle.