Reclusive, analytical, inventive and the most intelligent of the known dragon species.
PICKY EATER - If a Night Fury eats something it doesn't like, stand back. Flaming food flies fast.
KAMIKAZE BOMBER - Using the night sky to conceal its beautiful dark hide, it dive bombs villages, ships and armies virtually unseen and never misses.
Dive bombing, Speed, Agility, explosive fireballs
- "Speed: Unknown. Size: Unknown. The unholy offspring of lightning and death itself. Never engage this dragon. If you see it, hide and pray it does not find you." - Dragon Manual
- "Night Fury! Get down!" - Anonymous Viking
The Night Fury is a species of dragon that only appears in the movie adaptation of How to Train Your Dragon. Toothless is a Night Fury in the movie, in contrast with his original Common/Garden Dragon form in the book.
The Night Fury is the rarest and most intelligent species of dragon. It is small to medium-sized with a sleek, dark body that is almost black. It sometimes appears bluish and has faint lighter patterns similar to that of a manta ray. The Night Fury resembles an axolotl in general appearance and has two pairs of wings, two mobile, ear-like plates on the back of its head to show its mood, a second pair of plates in between each ear-like plate, and two just behind the jaw and beneath each ear-like plate, a pair of large, yellowish-green, cat-like eyes and sharp retractable teeth. Unlike most dragon species, the Night Fury has a short neck and lacks any kind of horns.
In flight, the Night Fury's wingspan is unrivaled, bearing approximately 48 feet, making it resemble some sort of jet plane. This allows it to fly faster, longer and further than any of the other dragon species. It uses the wing-like flaps on its tail to steer and maneuver, similar to an airplane rudder. However, a Night Fury will be incapable of flying if one of these flaps is missing or destroyed. Not only is this species fast in the air, but it is also very fast on the ground, running very fast on land and can even leap from tree to tree.
Night Furies are generally quite aggressive to any form of threat they find, similar to how the other dragons treat the Vikings of Berk. According to the Dragon Manual, the Night Fury is considered to be so aggressive that it is likened to the "unholy offspring of lightning and death itself". Toothless proves himself to be quite an advanced fighter when he manages to defeat a Monstrous Nightmare, one of the Vikings most feared enemies, and also quickly outmaneuvers and defeats many vikings including Stoic the Vast, who is presumably the best dragon slayer in Berk.
However, like their fellow dragons, Night Furies are seen to have a different personality when they are not threatened. They are curious creatures that attempt to understand new things they observe and are intelligent enough to attempt to recreate the actions that they see. Night Furies are fairly capable of communicating, seemingly understanding human speech: the best evidence of this is when he makes a noise in agreement with Hiccup regarding the fact the the Red Death can fly or when Hiccup orders Toothless not to kill Astrid and Stoick. Toothless also does not have a very hard time getting his emotions noticed: for example, Toothless growled when Hiccup stepped on his drawing, or snarled in disgust when Hiccup mentioned he put an eel in Toothless' dish.
A Night Fury's main type of attack style is dive-bombing at enemies at great speed while being completely camouflaged within the dark sky. The Night Fury is able to be completely invisible at night because of its dark colored scales. In addition of dive-bombing, the Night Fury will also spit out oxygen/acetylene-fueled flames that will explode upon impact and will instantly incinerate anything. Night Furies are picky eaters and will only eat fish. When hunting, a Night Fury uses its sharp retractable teeth as fishing hooks in order to snatch and grip prey from the water. Night Furies are also capable of completely swallowing prey whole and their stomach liquids, which are similar to battery acid, are strong enough to dissolve fish bones. When tamed, Night Furies are known to regurgitate half of their catch for their owners. As seen with Toothless, Night Furies have a penetrating, wolf-like or cat-like stare. The Night Fury is a very dangerous and elusive dragon and should be avoided at all costs, unless of course, one is able and willing to train it.
Night Fury's are said to be amazing fighters. They use their incredible explosive fire to damage any unlucky foe. They seem to be very agile in flying, using this to confuse their enemies. Also, Toothless can pounce on Vikings. He is also able to fight off Hookfang, a larger Monsterous Nightmare to protect Hiccup.
"The rarest and most intelligent of the dragon species, the Night Fury is distinguished by its dark color and piercing yellow eyes, as well as its smaller size, heavy chest and short neck. Possessing the largest wing-to-body ratio of all dragons, it can fly higher, faster and longer than any dragon, and its incredible power-to-weight ratio renders it capable of vertical takeoff. Its unconventional fire (a semi-solid mass alight with an acetylene/oxygen flame) explodes its target on impact. Its signature attack mode is executed after sundown and from high altitude -- enwrapped in its wings, it dives like a bullet, pulling up at the last moment to deliver one precise and explosive burst ... then vanishing back into the darkness. The only warning is the ballistic noise the diving Night Fury makes. Its kamikaze attack, along with its cautious behavior and analytical mind, makes the Night Fury a devastating opponent with an extraordinary success rate. To date, no Night Fury has ever been brought down."
"He's the Ferrari of dragons. Very, very fast. A lot of dragons have giant scales and are spiny. He has the clean, sleek look of a panther." 
"These stealthy, high flyers are so fast they're almost never seen, but just because they aren't visible doesn't mean they can't flame a viking village!"
- Despite having very little information in the Dragon Manual as well as only one seen in existence, Night Furies do not fall under the Mystery Class.
- The growls and croons of Night Furies and Toothless are a combination of various sounds, including Supervising Sound Designer Randy Thom, elephants, horses, tigers, and even domestic cats. 
- Toothless, a Night Fury, is the only dragon in the film adaptation to be given a personal name.
- Toothless may be the last Night Fury, as Hiccup said he has never seen another. However, it is possible that there's few-to-none in Berk.
- When it wants to burn something it has normal red/orange flames, but it's explosive/concussive flame is blue.
- Despite being picky eaters who "only eat fish", Dragons: Wild Skies mentions that Toothless also enjoys honeycombs and crab.
- ↑ 1.0 1.1 1.2 How to Train Your Dragon Official Website - Night Fury Dragon Characters Section
- ↑ 'How to Train Your Dragon' breathes fire into the film genre - USA Today
- ↑ Back of Walmart-Exclusive large Night Fury toy's box
- ↑ How to Train your Dragon Sounds, Interview with Randy Thom | SoundWorks Collection Exclusive