What is the train set in how to train your dragon 2 based on?

The live‑action film How to Train Your Dragon 2 is a direct continuation of the 2025 remake of the original 2010 animated movie, which itself was loosely adapted from Cressida Cowell’s 2003 book *How to Train Your Dragon*. The story follows Hiccup, a young Viking who befriends a dragon named Toothless and learns that dragons are not the fearsome enemies the Vikings have always believed them to be. The novel introduces the same premise of a bond between a human and a dragon, set on the fictional Isle of Berk, and provides the core characters, setting, and themes that the film series builds upon. While the film takes creative liberties—adding new plot elements, characters, and a more expansive visual style—the narrative foundation remains the same as Cowell’s original book. Thus, the entire franchise, including the second installment, draws its primary source material from that 2003 novel.