Alvin the Treacherous is a major character in the How to Train Your Dragon franchise, books and TV series. He is the main antagonist of the Book series, first appearing in the book "How to Be a Pirate". He serves as the main antagonist in the first season DreamWorks Dragons: Riders of Berk and the main antagonist turned anti-hero in the second season DreamWorks Dragons: Defenders of Berk. He is the Chief of the Outcast Tribe. He was voiced by Mark Hamill.