Carcharoth was created as a defence against Huan, and was reared by Morgoth's own hands on living flesh and filled with great power. So Carcharoth, who was also named Anfauglir (IPA: /anˈfaʊglir/), the 'Jaws of Thirst', grew to great size and his strength seemed beyond compare. His eyes burned like red coals and his teeth were poisoned as the spears of the Orcish legions. Carcharoth was the guardian of the gate of Angband and none could pass him by strength of body alone.
He became involved with the Quest for the Silmaril when Beren and Lúthien had to pass him on their way in. He espied them on their way in, and grew suspicious of Beren because he was disguised as Draugluin, who Carcharoth knew to be slain. Before he could take action against the pair, Lúthien enchanted him with her magic, sending him into a deep sleep. Unfortunately, on their way out Carcharoth awoke, and Lúthien was too weary to spell him again. Beren held out the captured Silmaril in an attempt to stay the beast, but Carcharoth was not daunted, and bit off Beren's hand at the wrist, Silmaril and all.
The Silmaril burnt away Carcharoth's insides, and he became crazed with pain, yet filled with great power. A terror to Eldar, Men and Orcs alike, he passed south through Beleriand, until he arrived in Doriath. There Beren Erchamion, Elu Thingol, Beleg Cúthalion and Mablung joined with Huan the Hound to Hunt the Wolf.
Carcharoth was killed in single combat by Huan in FA 466, but both Huan and Beren were mortally wounded by him. When Mablung cut open the belly of the beast, he found there the Silmaril with Beren's hand still around it, but when he touched the flesh it was swept away by a wind.