Maedhras vs Beren

One major similarity between Maedhros (Feanor's son) and Beren. Maedhros is ignorant and goes out on a parlay, which is actually and ambush. Morgoth captures him, attaches a chain to his wrist, and leaves him hanging over a cliff. A friend hears him singing, and risks his life to rescue him. He can only free him by cutting off his hand. Beren is on a quest to steal a Silmaril from Morgoth. He gets in and takes one, but he meets the largest wolf (who killed Huan). He shows the wolf the Silmaril out of pride, as if saying, "I won, you failed." The wolf bites off Beren's hand, swallowing the Silmaril. Even though their tales are quite different, they both end up with one hand.

Huan

Huan is a dog from the Silmarillion, who can only be killed by the biggest wolf to ever live. He also gets to talk three times in his life. So he understands what people say, and he has amazing senses (i.e. smell, sight, etc.). He is Beren and Luthien's companion. He goes with them on their adventures, and his life ends after fighting a wolf fed by Morgoth himself, not just fed with food, but he is fed with malace and the like. The two have a tremendous battle, but Huan ends up dying, because it was the biggest wolf who ever lived. He uses his last time talking while he is dying. His story may not be a happy story, but it is a story of love and loyalty.