The Water Dragon first appears in Book 5, How to Twist a Dragon's Tale.
Interesting to note: The "Viking Dragons and Their Eggs" Info sheet in How to Twist a Dragon's Tale indicates Water Dragons originated from deserts in Asia.
These extraordinary-looking creatures are covered in vicious-looking spikes, including a large spike at the tip of their snout. Water dragons have sharp claws and large bat-like wings, as well as a hooked and spiny tail and large eyes. These dragons seem to come out in shades of yellow and brown. Most notable however is the large hump on their backs, similar to a camel. Water Dragons are large enough to be Riding Dragons.
Water Dragons are so called because they can swallow large amounts of water and store it in their rather flexible stomach. They can also store water in their humps like a camel. The water can be expelled in a very forceful jet, able to stun prey and knock a Viking over.
Water Dragons co-exist with Firestarters and are the only reason the Flaming Forest survives. If the fires threaten to burn out of control the Water Dragons put them out. Because Firestarters are classified as Tree Dragons, and live with the Water Dragons, Water dragons might also be viewed as Tree dragons. Also, they are discussed in the Tree Dragon Section of The Incomplete Book of Dragons.
Water Dragons have a 'Disobedience' rating of 2, making them highly trainable dragons. The Hairy Hooligan Tribe uses them in particular to put out fires.
Book 5 details the existence of a 'Fire Brigade' on Berk. It consists of trained Fire Warriors riding Water Dragons to put out any fire that might arise. This is a constant possibility when living with dragons!
Water Dragons are discussed in this Reference book along with Firestarters in the Tree Dragon chapter.
- The Water Dragons in the Hero's Guide to Deadly Dragons on the Official How to Train Your Dragon Books Website.