Changewing

The Changewing has large wings on its back, horns on its face and an antennae-like appendage on top of each of its eyes. This gives the Changewing a unique appearance. This dragon appeared in "Gem of a Different Color". It also had a cameo in the film, along with a section in Book of Dragons.

Dragon Appearance
The Changewing's most noticeable attribute is the ability to change the colors of its scales and wings to that of its surroundings, creating an invisible-like effect. Unlike most other dragons, the Changewing can launch concentrated streams of acid at victims.

This acid can burn through most, if not all, materials in seconds. Another known feature of this dragon is the unseen ability of hypnotism, only seen in the 2D animation in Book of Dragons so far. The Changewing's skin is vulnerable to attack, as it is softer due to its color-changing properties.

Changewings nest in large, tall forest in packs. They group together for common goals, or in other words, they are team players, and will stop at almost nothing to remain in possetion of their eggs. Also, Changewings are very curious creatures, and like to mimic everything that they see.

A Changewing's egg has gem-like qualities and are green in base, but its aura glows in multiple colors. Some vikings will mistake these for "Stones of Good Fortune".

Changewings are known to be very cooperative and work together to accomplish their goals. Multiple Changewings help one another acquire one of their eggs, and do not rest or leave until all of their eggs have been found.

In the Book of Dragons
In the Book of Dragons special, they are listed as one of the Mystery Class type dragons, and it is confirmed that not only can Changewings spit acid, but change colors and hypnotize as well. It is also shown that Changewings are very curious dragons. They are seen in a 2D animation where one burns Bork the Bold while he is making a campfire. The mystery class symbol also looks like one.

Dragons: Riders of Berk
The Changewings appears in "Gem of a Different Color". Fishlegs, on his own "secret" island, finds a strange glowing gem while with his beloved dragon Meatlug. Taking it back to Berk, Gobber identifies it as a "Stone of Good Fortune,"(as Gobber gets "stones of Good Fortune" and Changewing dragon eggs mixed up) causing the citizens to swarm Fishlegs, offering him valuable trades. Overwhelmed, Fishlegs, after refusing to give it to Snotlout, asks Hiccup to help him return it, so that Fishlegs can forget all about it.

They, excluding Snotlout, who is secretly trailing, take it to the island, where they find many of them, and Hiccup realizes that they are truly dragon eggs. Fishlegs returns it, realizing that it must've fallen from its nest and that he had seperated it from its mother. When they attempt to leave, the Changewings trail them, invisible, trying to attack them using their acid. They escape, but Snotlout enters undetected and steals many of the eggs. The next day, Snotlout auctions them off, and the gang tries to convince him something terrible will happen if they remain here. He ignores them and declares a, "No returns" policy. The Changewings gradually show up, getting their eggs back, but destroying the village in the process. Stoick and Gobber try to fend them off, but realize that it would be impossible to attack the things they can't see.

Hiccup and the gang scramble to return the eggs, and they end up with giving them all back, but the Changewings don't leave. Fishlegs realizes Snotlout has kept one and Fishlegs confronts him, displaying anger and strength that scares Snotlout into giving it back. Fishlegs then nervously tries to find them, and the Changewings surround Fishlegs and reclaim their egg from him. Afterwards they roar and terrify the unfortunate viking but leave him completely unharmed. Hiccup later claimed they would need to find one so they could train it, possibly infering they will later appear again.

A Wild Changewing as well as a Wild Thunderdrum appear in  "We Are A Family Part I" where it hides an entrance to the cave and "holds Snotlout hostage" until Hiccup frees him.

Appearances

 * How to Train Your Dragon (film) (Mentioned)
 * Book of Dragons (Mentioned)
 * Gem of a Different Color (First appearance)
 * We Are Family Part I (Wild Changewing)
 * We Are Family Part II (Outcast Changewing)
 * Live and Let Fly (Herd of wild Changewings and Outcast Changewings)
 * Free Scauldy (Herd of wild Changewings)

Notable Changewings

 * Changewing that Bork met (see Book of Dragons)
 * Group of Changewings (see Gem of a Different Color)
 * Wild Changewing (see We Are Family Part I)
 * Outcast Changewing (see We Are Family Part II)
 * Wild Skies Changewing
 * Three wild Changewings and three Outcast Changewings ( see Live and Let Fly)
 * Group of Changewings ( see Free Scauldy )

Trivia

 * The Changewing is one of the mystery dragons in Wild Skies along with the Smothering Smokebreath.
 * Strangely, according to Book of Dragons, the Changewing breathes acid instead of fire while the special shows one burning Bork the Bold. It could be that their fire is greatly reduced compared to other dragons.
 * In Gem of a Different Color, it is shown that the Book of Dragons doesn't contain a picture of the Changewing, but in the movie, there was a picture of the Changewing in the same book.
 * The Changewing's facial appearance is similar to that of the Diplocaulus, a type of extinct, prehistoric amphibian.
 * The Changewing's size is similar to the Monstrous Nightmare.
 * In the end of the episode of Gem of a Different Color, it was hinted that the Changewing could possibly be trained in a later season.
 * The Changewing's ability to mimic its surrounding in the episode of Gem of a Different Color,  is different from what's shown in Book of Dragons, its color mimicry in Book of Dragons is fixed on every part of its body while in Gem of a Different Color, Changewings mimic different colours for different parts of its body, even if it's not in contact with Changewings body making it truly invisible with a little distortion.
 * The Changewing makes a second appearance in We Are Family Part I.
 * It makes a third appearance as a hostage of Alvin the Treacherous in We are Family Part II.
 * Changewings are red in the animation, but in the Book of Dragons the one was a greenish-blue. The Book of Dragons on the Cartoon Network website has an icon of a green Changewing. It's possible that female Changewings are red and male ones are green, or that this was simply the dragon changing its' colour.
 * A Changewing's ability to hypnotize is most likely based of the books, where dragons have a hypnotic gaze.
 * While Changewings in the animated short, Book of Dragons, camouflage themselves in a chameleon-like way by changing color, in Riders of Berk they disappear completely. In Wild Skies they disappear almost completely, however a faint outline of the dragon is still visible.
 * Changewings are also very caring as seen with a Changewing that played with Snotlout.
 * So far, all the appearences of Changewings have had an antagonist role in the series.