Legend of the Boneknapper Dragon

The Legend of the Boneknapper Dragon is a short 15-minute film with the How to Train Your Dragon Blu-Ray disc. It stars the original cast of How To Train Your Dragon and combines both CG and drawn animation.

Plot
The film opens with a fire seen raging inside Gobber the Belch's house. Stoick orders a group of Nadders and Gronckles to help, dumping water over the house in an effort to put it out along with the other Vikings. Eventually, the flames are extinguished and Gobber comes out of the house with his possessions, claiming to know what caused the fire. As Hiccup gets off Toothless' back, he asks Gobber what he's talking about, causing him to claim the Boneknapper Dragon has hunted him down again, a beast that will stop at nothing to create the perfect coat of armour made entirely of bones. Stoick and the rest of the vikings refuse to believe his claims as Gobber decides to hunt down the beast once and for all with his pet sheep Phil in tow. Worried for his wellbeing, Hiccup persuades his friends to help Gobber search for the Boneknapper.

While traveling on their ship, a seven-man longboat, Gobber reveals his backstory of how the Boneknapper had started to hunt him down. He revealed that when he was a teenager on a summer vacation trip with his parents, he stopped inside an frozen cave for a bathroom break and was surprised to see a wall of ice with Vikings trapped inside. Gobber noticed that one of the Viking was holding a treasure chest and decided to claim it for himself. It was here that the Boneknapper appeared and began to chase after him. The Boneknapper flew after Gobber until he escaped with the treasure box.

In the present, the group ends up crashing their boat on some rocks and get stranded on a distant island with no way off. Gobber explains his second encounter with the dragon, when he was stranded on an island himself many years ago, armed with only his broom arm attachment. The Boneknapper found him again, causing Gobber to flee though an ocean filled with Hammerhead Sharks. His story then becomes more wild when he claims a Hammerhead Whale attempted to eat the Boneknapper, but failed. The group, almost unsurprisingly doesn't believe him, but Gobber is determined to prove the Boneknapper exists. He comes up with a plan to capture it once and for all, using Fishlegs as bait.

While they are waiting for the Boneknapper to try and attack a disguised Fishlegs, Gobber tells of his third encounter with the dragon. Still some years ago, Gobber found himself in a forest with only an egg beater arm attachment with the Boneknapper pursuing him relentlessly through the trees. Gobber claims to have climbed up and leapt over the crater of a volcano, where a Hammerhead Yak jumps out and saves him from the dragon. The Boneknapper still survived, prompting Gobber to lay out a series of traps to try and stop his predator. The BoneKnapper surfaced once again and chased him through the forest, managing to avoid everything he had set up. The BoneKnapper chased Gobber all the way to a cliff, where he was saved by Thor himself tossing a thunderbolt into the ground and summoning the Hammerhead Yak riding the Hammerhead Whale.

Distracted by this story, nobody notices the Boneknapper finally showing its face, making a squeaky sound in its failed attempt to roar, causing the group to realize that Gobber was telling the truth about the Boneknapper (if not about the yak, in any case). Gobber's trap fails and ends up trapping the group beneath a gigantic ribcage of bones. As the Vikings take cover behind the ribs from the Boneknapper's fire, Hiccup realises that the treasure that Gobber found, a belt buckle made of bone, is what the Boneknapper wants to obtain his roar, after noticing the small piece missing from his neck plate. Despite the group's initial objection of Gobber removing his pants, the old Viking is eventually convinced (after being grabbed by the peg leg and shook about quite violently) and gives the bone back to the dragon, who then finally gets his roar back. Having completed its objective, the Boneknapper becomes docile and thankful toward Gobber and the group is able to ride it all the way back to Berk (with Phil on it's head), followed by other Boneknappers joining them in flight (as stated by Fishlegs, that the Boneknapper's roar is its mating call). With that in mind, Gobber is certain that Stoick and everyone else in Berk will believe him now.

Trivia

 * Gobber's pet sheep, Phil, is introduced.
 * While most of the short is done in CGI, Gobber's flashbacks are done in a 2D animation style.
 * It appears that the Boneknapper dragon is now Gobber's dragon mount.
 * Toothless makes a small cameo, when they are putting the fire out and when they are all in the Great Hall. In fact, the kids' dragons, with the exception of toothless, only appear when they are putting the fire out.
 * Gobber's tale depicts the Hammerhead sharks tryng to attack him while in real life, sharks don't really attack people intentionally.
 * When the Vikings set off to find the BoneKnapper, Hiccup is wearing his fur vest. When riding the BoneKnapper at the end, he's wearing his riding vest.

Errors

 * In the movie, while talking to the viking teens around a camp fire, Gobber mentions that he lost his hand to a dragon. This is followed immediately after him commenting: "He must have passed the word because it wasn't a month before another one of them took my leg!" (Gobber never states which breed of dragon caused either injury and also states that the Boneknapper is only chasing him to get the treasure back). If Gobber's second encounter with the Boneknapper took place immediately after the loss of his hand, then by the movie's dialogue, he shouldn't have still had his leg by the third encounter if the short's dialogue states that years went by in-between his encounters or a simple mistake made by the writers.
 * In beginning of the scene when Hiccup, Astrid, Snotlout, Ruffnut, Tuffnut, and Fishlegs are struggling to row the longboat, a mast is present. In the next similar shot, when the Vikings are listening for the Boneknapper's silence, the mast is gone.
 * Right after Gobber gives the Boneknapper dragon its bone, the dragon roars but the hole where the missing bone was located is still there.