The Warrior Cats Series is a popular collection of children's novels written by Erin Hunter. The series follows the adventures of wild cats living in clans, each with its own territory, traditions, and leaders. The main storylines revolve around themes of friendship, loyalty, and survival as the cats face challenges from rival clans and the dangers of their environment. The series began with the first book, Into the Wild, published in 2003. It has since expanded to include multiple arcs, spin-off books, and graphic novels, captivating readers with its rich world-building and complex characters. The series encourages themes of bravery and the importance of community.