Foreverwing

"The Bells of Frey will wake the sleeping giant. For it stays hidden if too silent. Over trees, and under seas. To wake this dragon ring all three."

- A legend, as told by Gothi

The Foreverwing is a Mystery Class  dragon introduced in Rise of Berk before appearing in The Serpent's Heir. The Foreverwing is said to share a special, almost telepathic connection with Hiccup.

Official Description
"The Foreverwing resides in a mountain side hidden by trees and rocks. It is the perfect camouflage for this Dragon, which would rather spend its time sleeping! So make sure it’s not disturbed!"

- Dragons: Rise of Berk

Development
As shown by concept art by Ludia, the Foreverwing's inspiration from nature seems to be evident from early concept already. All five sketches resemble woody, plant-like landscapes, and these features--branch-like protusions, bumpy skin and an ancient-like appearance--runs true in every sketch.

Most concept focus more on the lower jaw shape of the Foreverwing, as well as the frill at the back of their heads. Earlier concept depict the frills somewhat more fin-like.

Hatchling to Adult
The Foreverwing is a colossal dragon. It has a woody brown colour and the what seems to be like branches at the back of its head and below its chin. These 'branch-like' objects resemble hair and a beard. With small, kind eyes and an aged appearance, this dragons looks rather old and wise. The Foreverwing has thick foliage such as trees and vegetation on its back.

Behavior and Personality
The Foreverwing enjoys sleeping most of the time and does not like to be disturbed. Its stillness when sleeping also contributes to its great camouflaging abilities. This dragon appears to be lazy and has a huge temper when it is awakened without its consent.

Camouflage
The Foreverwing uses the foliage on its back as camouflage that leads others to think that it is just part of a mountain side. The dense foliage on its back covers almost its entire body, except for its head and limbs. Their body, by itself, resembles wood and earth. Thus, even when its head is revealed, it is hard to spot a Foreverwing. This may help it hunt, escape, or even simply get some sleep undisturbed.

Command
The Foreverwing, like the Red Death, the Bewilderbeast, the Screaming Death and other alpha species, have loyal subjects under its command; the Foreverwings are known as Seedling Dragons. The Foreverwing seems to be a benevolent leader, and does not treat its subject dragons harshly. They are seen openly flying around it in most of its artwork.

Telepathy
The Foreverwing is capable of telepathy and according to Rise of Berk, it shares a special, nearly telepathic connection with Hiccup, though why or how this is done is unknown.

Calming Compounds
The Foreverwing is able to produce some kind of compound with a sedative effect that enables it to sleep for long periods of time. As seen in The Serpent's Heir, dragons that bathe in water collected on the body of the Foreverwing will be calmed by these compounds and are eventually sedated.

Firepower
The Foreverwing produces copious amounts of lava, which is powerful enough to destroy entire villages.

The Serpent's Heir
At some point prior to the first and second film, the people of Nepenthe built their home upon the forested backs of six Foreverwings, unaware that these massive dragons lurked beneath their feet. The people also swam and bathed in the hot springs formed by water collecting on the Foreverwings.

Following the ascension of Hiccup Haddock III to Chief of Berk and the Hooligan Tribe in How to Train Your Dragon 2, Hiccup and his riders were asked by Calder to assist them in finding the cause of the tremors during the events of The Serpent's Heir. The dragons, except for Stormfly, Skullcrusher, and Cloudjumper, bathed in the water that had collected in the nostrils of one of the Foreverwings, leading to them being calmed by the compounds that keep the Foreverwings asleep and left them an easy target for Calder. The movement of the Foreverwings were revealed to be the cause of the tremors, and after a large battle against Calder and his men, the six of them woke up, spewing lava everywhere and destroying the village of Nepenthe. Fortunately, Hiccup and the rest of the Dragon Riders were able to save the people of the island and Toothless used his Alpha position to calm the Foreverwings down. He told them to leave Nepenthe in peace, and all six of them left the island in various directions to find new places to sleep.

Dragons: Rise of Berk
The Foreverwing is the first titanic dragon that was created for Rise of Berk. Unlocking this dragon unlocks a new logging spot, boosts logging speed and unlock a series of new dragons called 'Seedlings', as well as the achievement 'Wake Up Call'.

Trivia

 * For some reason, one of the Foreverwing's feet is often seen inside a cave. Why it keeps it there is unknown, but it could be a referenced to a turtle or tortoise because the mountain side acts as a shell.
 * The Foreverwing's personality is similar to that of a Hotburple.
 * The vegetation on the Foreverwing's back might relate to Fishlegs' description from the first movie of a dragon that had spines that looked like trees.
 * Foreverwings sleep for so long and are so rare that even Valka believed they were only a myth.
 * The Foreverwing is the third dragon believed to be a myth to be proven to be real, with the other two being the Boneknapper and the Smothering Smokebreath.
 * The Foreverwing is so far the only non-Boulder Class dragon that can breathe lava.
 * Even though they were stated to be able to control dragons and have a telepathic connection with Hiccup, they seem to lack these abilities in The Serpent's Heir.
 * The Foreverwing is the only dragon species to have originated in Rise of Berk that was moved into main canon via the novels.