Carcharoth, also known as the Red Maw, or Karkaroff, lived in the First Age of the Sun, the greatest werewolf who ever lived, a beast of the line of Draugluin reared by Morgoth 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. The walls of Angband were sheer and dread chasms of serpents lay on either side of the road and Carcharoth lay unsleeping before the gate.
He became involved with the Quest for the Silmaril when Beren and Lúthien had to pass him on their way in. Lúthien enchanted him with her magic, but on their way out Carcharoth attacked before Lúthien could enthrall him again. Beren held out the captured Silmaril in an attempt to stay the beast, but Carcharoth bit off Beren's hand at the wrist with Silmaril and all.
The Silmaril burnt away Carcharoth's insides, and he became crazed with pain. 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 by Beren and Huan in FA 466, but both Beren and Huan were slain. 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.