Legend of the Boneknapper Dragon

Legend of the Boneknapper Dragon is a 2010 American computer-animated short film produced by DreamWorks Animation and set within the How to Train Your Dragon universe. The film features most of the cast from the original film reprising their roles, and follows Hiccup and his young fellows accompanying their mentor, Gobber, on a quest to kill the legendary Boneknapper Dragon. It originally aired on television via Cartoon Network on October 14, 2010, and was released as a special feature on Blu-ray and double DVD editions of How to Train Your Dragon the next day.

Plot
The film opens with Gobber's house on fire and the Vikings and resident dragons getting it under control. Gobber is convinced that his old nemesis The Boneknapper Dragon, a giant, yet perfectly silent dragon (the only one with no roar) that clothes itself in bones for armor, is responsible. However no one else believes that the Boneknapper even exists, much less that it burned his house, especially when the evidence suggests that the fire was started by his underwear drying at his hearth and catching fire.

Undeterred, Gobber vows to hunt down the beast once and for all and Hiccup reluctantly decides that he cannot let his mentor go alone, so he convinces his Viking recruit comrades to join him as well. As the gang row to the island where Gobber believes the dragon lives, Gobber tells them of his past encounters with the monster, shown to the viewer in traditional animation. He apparently first met it when he discovered a group of frozen Vikings after he relieved himself on an iceberg during a family outing and he extracted a small treasure chest from the ice. As the frozen Viking he stole it from resisted by punching him in the face a couple of times, the Boneknapper appeared and chased him until he landed back in the family boat. The contents of the chest turn out to be a small bone that Gobber has since used as a belt buckle.

The stories continue, becoming increasingly ridiculous as Gobber tells of later encounters with the Boneknapper being interfered with by hammerhead sharks, a hammerhead whale, a hammerhead yak jumping out of an active volcano and the Norse thunder god Thor. Unfortunately, the group's attention is so occupied that they allow their boat to run aground and sink. Taking the loss of their only way home in stride, Gobber sets up a trap using Fishlegs as bait. The gang still refuses to believe Gobber's claims, but unfortunately, a real Boneknapper silently comes up from behind the group and Fishlegs' attempts to warn them are ignored until it is in position to attack. At the same time, the Boneknapper makes a squeaky sound in its failed attempt to roar. Realizing that Gobber was telling the truth about the Boneknapper all along, the gang has to take shelter inside their own trap. All seems lost, but Hiccup sees an empty spot on the dragon's neck armor that exactly resembles Gobber's belt buckle bone. Hiccup realizes that the Boneknapper may simply be seeking to reclaim it from Gobber to complete his armor and be able to roar.

Gobber initially refuses to heed Hiccup's advice to placate the creature. However, he is soon seized by the beast and finally gives in. He throws the bone back at the dragon; the bone lands perfectly in the empty spot and the dragon is finally able to triumphantly roar with his armor completed. As it turns out, the satisfied Boneknapper is a friendly one and Gobber finally develops a newfound love and respect for the creature. The adventurers then ride the Boneknapper, presumably towards Berk. As Fishlegs informs the others that the dragon's roar is a mating call, four other Boneknappers appear from the distance. Gobber notes that he will definitely be believed this time.

Voice cast

 * Jay Baruchel as Hiccup Horrendous Haddock III
 * America Ferrera as Astrid Hofferson
 * Gerard Butler as Stoick the Vast
 * Craig Ferguson as Gobber the Belch
 * Christopher Mintz-Plasse as Fishlegs Ingerman
 * Jonah Hill as Snotlout Jorgenson
 * T. J. Miller as Tuffnut Thorston
 * Kristen Wiig as Ruffnut Thorston