"How to Train Your Dragon" is a popular animated film series based on the books by Cressida Cowell. The story follows a young Viking named Hiccup Horrendous Haddock III who lives on the island of Berk, where dragons and Vikings are traditionally enemies. Hiccup befriends a dragon he names Toothless, which leads him to discover that dragons are not the fierce creatures everyone believes them to be. Throughout the series, Hiccup learns to communicate and bond with dragons, changing the way his village views them. The films explore themes of friendship, bravery, and understanding, showcasing Hiccup's journey from an outsider to a respected leader among both Vikings and dragons.