Born into the same unlucky family as his deadly sister, Lionclaw despised his sister greatly after she nearly drowned, scolding her until they were apprentices and even after that on occasion. He had a pretty normal apprenticeship, outside of the one thing he knew his sister had done. She had killed the deputy in her sleep - and he always wondered how she did that.
Greatly affected by the death of the deputy, Lionpaw was determined to reveal his sister's treachery. In fact, he even worked with Quailpaw, whom eventually would be close to his sister, in finding a way to exile her. However, his plan remained between them until after Falconfeather became a queen.
At last, Lionclaw and Quailfeather's plan played out, sucessfully revealing her closeness to Cerberus and her killing of a long-deceased deputy. As they laughed as she shook and fell to the ground during her exile, none of them thought she'd find a way to get them back.
Moons later, after they had both moved on, Quailfeather was suddenly killed by none other than Falconfeather. Lionclaw was fiercely angered by the death of his friend, and vowed to kill her himself, of which he eventually did but died of his wounds in the same brawl.