Dragons frequently attack the Viking village of Berk, stealing livestock and endangering villagers. Hiccup Horrendous Haddock III, the 16-year-old son of chieftain Stoick the Vast and an apprentice to local blacksmith Gobber, attempts to create mechanical devices to overcome his physical weaknesses. During a dragon raid, Hiccup shoots down a rare dragon called a Night Fury with a bolas launcher, but is disbelieved. Vowing to prove himself, Hiccup searches for the dragon to kill it. Upon seeing the dragon helpless and wounded, he compassionately releases him. To Hiccup’s surprise, the angered dragon spares his life.
Meanwhile, Stoick rallies his fleet to destroy the dragons’ nest. Before leaving, Stoick heeds Gobber’s advice and enrolls Hiccup in a dragon-fighting class with other local teens: Fishlegs Ingerman, Snotlout Jorgenson, the Thorston twins Ruffnut and Tuffnut, and Hiccup’s crush, Astrid Hofferson. Hiccup is mocked by his peers and struggles in class. Returning to the forest, he finds the Night Fury trapped in a cove, unable to fly because Hiccup’s bolas severed half of his tail fin. Hiccup befriends the dragon, naming him “Toothless” for his retractable teeth; he builds a harness, saddle, and prosthetic fin, allowing Toothless to fly with Hiccup riding on his back to guide him. Hiccup also learns about dragon behavior from Toothless, which allows him to subdue the captive training dragons, impressing the villagers, but arousing Astrid’s suspicions.
Meanwhile, Stoick’s fleet is damaged while searching for the nest, and returns to Berk. Upon learning he must kill a dragon for his final exam, Hiccup attempts to flee with Toothless, but Astrid discovers them. Hiccup takes her on a flight to show her Toothless’ friendliness. During the flight, Toothless is drawn to a dragon’s nest, where a gigantic dragon, the Red Death, commands smaller dragons to feed it to avoid being eaten themselves. Realizing the dragons attack Berk for survival, Astrid wants to inform the villagers, but Hiccup advises against it to protect Toothless.
