Fang

The Night Fury is a species of dragon from the fictional How To Train Your Dragon universe. According to the Dragon Manual, the Night Fury is considered to be so mysterious and feared, that it was often called the "unholy offspring of lightning and death itself." Furies are generally very reclusive, wary, and aggressive to any form of threat. They are not easily scared. Furies are described as the fastest, most intelligent, and most mammalian kind of dragon. It is said to be the only dragon known to reach speeds that break the sound barrier. On land, they can outrun and outmaneuver most other dragons and are capable of leaping from and landing on vertical surfaces. Furies are also incredibly strong and have flexible prehensile tails. They are defined by their characteristic trait of retractable claws and teeth. Their scales are extremely dense and impervious to other kinds of dragon fire, but can be penetrated by dragon-root wood.

The Night Fury was once considered to be one of the most mysterious and fearsome species of dragons. For a long time, the only information that the Vikings had gathered on this rare dragon was the whistling sound of its speed cutting through the night sky, followed by a bright purple light, then finally a massive explosion. Their appearance at this point was entirely unknown, as they are nocturnal hunters, black scales allowing them easily to blend into the night sky and making them mostly invisible. Physically, they are of medium build with jet black scales with paler patterned markings that allow them to camouflage in the night sky. These markings have been compared to those of the manta ray. Mature dragons typically reach 26-28ft in length with an average wingspan of 45-50ft.

Night Furies possess large yellow-green eyes with vertical slit pupils. They have excellent night vision and are capable of hearing over long distances. Night Furies have been known to use echolocation during periods of low visibility, such as snowstorms. They first emit a signal taking the shape of purple-coloured sound waves, which bounce off the surrounding environment and create a type of 'audio-map' that allows dragons to position themselves, find objects, and avoid obstacles, even in mid-flight. Unlike bats, this signal, or at least part of it, is still low enough to be within the human hearing range; humans can therefore locate the dragon using the signal.

Unlike many dragon species, the Night Fury lacks any kind of horns or spikes, only having flaps and aerodynamic fin-like appendages. Their short fin-shaped spines prevent greater air resistance than tall sharp spines and give the Night Fury a huge advantage in high-speed flight. At a certain age, the spinal flaps divide along the sagittal plane into two halves, allowing for greater aerodynamic maneuverability. The Night Fury’s aerodynamic wings and sleek body allow them to fly at supersonic speeds, faster than any other dragon apart from the Light Fury. It uses the fins on its tail to help steer and maneuver, similar to an airplane rudder, and as ballasts in flight. A Night Fury with a damaged or missing tail-fin may be unable to or have difficulty flying. Night Furies are capable of taking flight from a standing position, like pigeons. Furies are also strong swimmers and can hold their breath for extended periods of time.

Night Furies are solitary carnivorous apex predators whose diets consist mainly of fish, but can also include shellfish, red meat, and honeycomb. In spite of the occasional foraging, Furies are known to be strictly anti-scavenging, and highly possessive of their meals. Their preference for fish makes it likely that they developed according to a coastal or near-water niche.

These dragons are classified as members of the Strike Class, as they have the ability to dive-bomb their targets. Night Furies fold their wings to create a streamlined shape while they dive from the sky, helping them to achieve greater speed while they accelerate downwards. It has been observed that at the last moment, Night Furies open their wings to create the drag and lift off. The resulting impact of air can do great amounts of damage. The approach of a Night Fury is almost always accompanied by a high-pitched whistling sound.

Rather than breathing fire like other dragons, Night Furies are distinguished by their ability to expulse "plasma blasts" from their mouth. These bursts of pale-coloured flames are composed of ionized oxyacetylene. Plasma blasts explode directly upon impact, but may sometimes explode in midair at higher altitudes due to lack of oxygen supply. The Night Fury's plasma blast may reflect off of certain types of rock. A plasma blast may combine with lightning in an electro-plasmatic reaction to form a sort of mid-air seismic charge or supernova. Night Furies' shot limit is stated to be six plasma blasts, however, they have been witnessed firing 14-15 blasts in rapid succession. It is possible that the limit is in fact six, but that the reload period is extremely brief.

Unlike Light Furies, Night Furies' colouration means that they cannot easily cloak themselves with plasma; however, by absorbing high amounts of electricity from electrical storms, they are able to create an amplified plasma blast to turn their scales into a reflective cloak. Cloaking can also be accomplished when a Fury immerses itself within one of its own plasma blasts. As a Night Fury enters its 'cloaked form', it causes a massive wave of electrical energy that electrocutes everything within a close radius. While highly efficient, plasma cloaking is also an extremely taxing move that uses a lot of energy. It is implied that plasma cloaking is a learned behaviour acquired through socialization rather than an instinct.

Night Furies are said to be the most intelligent kind of dragon and are fiercely loyal. They have been described as having behaviours similar to big cats. They are highly accurate and lethal solitary predators that rely on stealth for both offence and defence. Night Furies are also shown to be both curious and creative, attempting to understand and replicate observations. They can be incredibly playful, intrigued by the littlest of things like flying sparks. Night Furies are also highly expressive dragons. Their pupils dilate may dilate or constrict when startled, agitated or focused. Earflaps and fins are also used in expression, perking and drooping to convey emotional state. The high intelligence of Furies means that they are trainable and capable of rudimentary communication with other species. They are also highly adaptable dragons and have been witnessed operating on diurnal schedules despite their natural nocturnal inclination.

Despite their solitary nature, Night Furies seem to be socially inclined and are eager to interact with other kinds of dragons. Night Furies display a high level of emotional and sentimental awareness of both humans and other dragons alike. These dragons are observant and evaluative and display heightened awareness and empathy towards their surroundings.

Night Furies may sleep in caves or outdoors, hanging from trees or on the ground. When sleeping in tress the body is positioned upside down with the base of the tail secures around the branch, tail fins hanging directly in front of the face, and wings wrapped loosely around the body. A similar position is used in caves, although it appears the tail is needed differently and does not hang downward. When sleeping terrestrially, Furies singe the ground with their plasma breath while walking in a circle, much as many mammals might circle before laying down. It is theorized that plasma fire is used to clean the sleeping space of debris while creating warmth.

During dominance displays, a Fury's dorsal spines, interocular ridge, inside of the mouth, and nasal canals glow bright a translucent blue as it charges a special kind of plasma shot. After having fired the shots, the bodily glow slowly fades away. There appears to be no shot limit during these dominance displays, of which all dragons are apparently capable.

While Night Furies are known to mate for life, the exact details concerning courtship rituals remain unknown. Night Fury eggs are oblong, almost similar to that of a chicken egg, and with a smooth texture. The eggs are jet black with paler patterned blemishes that serve camouflage purposes, similar to the mature scale colouration.

Like other species, Night Furies are susceptible to common dragon weaknesses. They are allergic to eels, can be poisoned by blue oleander flowers, are affected by grimora parasites and can be weakened by dragon root. Like all dragons, Night Furies are also susceptible to Deathgripper venom, with one vial being enough to subdue one into submission or knock them unconscious. Night Furies are not suited to cold weather or arctic environments. They are unable to fly long distances or for long periods of time without rest.