As an apprentice, Lionpaw caught the Clan leader Pinestar spending time with the Twolegs and eating kittypet food. Lionpaw urged Pinestar that RiverClan was invading, but Pinestar wanted the apprentice to tell the Clan he was dead so he could become a kittypet. Instead, Lionpaw encouraged his leader to tell the Clan himself and he probed the Clan's preference for a leader unwilling to lead. As he left, Pinestar stated he would have named him Lionheart, a name Lionpaw later earned by Sunstar.