Lycus is a gray and black wolf with blue eyes.
When Lycus lived with his wolf pack, he was always ignored by his family because he was the runt of the litter. He secretly befriended a rogue named Fallen Shadow. He told Lycus that he should leave and too stop being abused and to leave his pack. The pack killed Fallen Shadow to keep him from telling Lycus to leave. He fell into a deep depression because his best friend died. When Lycus' pack was attacking ThunderClan, he escaped and lived with ThunderClan.
Now, Lycus is a young adult. He is much stronger now and is plotting to get revenge. During the fight with the badgers, he killed the badgers not to protect the clan, but more for the sake of just killing. He can speak perfectly fluent cat now, but his words are very harsh and cruel most of the time.
He is now a Lone Wolf because he left ThunderClan after he attacked Skyfall for calling him a "dumb wolf."