The Boneknapper dragon is a dragon of mysteries. Its hide is made out of bones from dead dragons. In the “Legend of the Boneknapper”, Gobber said that it has been chasing him for years when he found a small chest in the ice on the side of a mountain. This happened when Gobber was on “vacation” with his parents. In the chest was a bone, and when then chest was in the ice there was a Viking holding it. That bone later was discovered to be part of the Boneknapper’s armor / skin.
The Boneknapper is a dragon of stealth. When the Boneknapper has spaces left for bones it can’t roar, but it can breath fire. When the Boneknapper has a full body it can roar so strongly that it can push a Viking back 10 yards (and make Gobber‘s pants fall down).
This dragon can sometimes act like a Night Fury. After all, when you first meet them, they can be defensive, but when you earn the dragon's trust, they can act as a giant pussycat.