In both book and film series, many of the dragons are shown to possess unique types of breath weapons. These differences make the dragons attacks much more unique. Here are some examples. This ability specially makes dragons unique, and put them 'different' from other organisms, and even capable of confront human beings armed with artificial weapons and group strategies. Every dragon's fires are fuel-based, and are different. Firepower is enhanced through combinations of unique sources of ignition and particular fuels. This can, however, be a weakness, as dragons aren't fireproof on the inside; an alert dragon can ignite another dragon's fuel the moment before the dragon itself does, causing the fuel to burn inside the dragon. The effect of this varies, from a slight daze to permanent wing damage.
Based on scenes in How to Train Your Dragon 2 when dragons of Berk and Dragon Den were released from hypnosis caused by Drago's Enslaved Bewilderbeast and counterattacked this massive enemy together, possibly all the fire-breathers are capable of differentiating flames of normal and in explosive, ball shaped blasts.
The fire that the Armorwing produces is a combination of Oxygen and Acetylene. It uses its fire to weld and create metal armor to protect its soft body. While the Armorwing's fire is incredibly hot, it is also incredibly bright, as it can temporarily disorientate the vision of other dragons. The fire consistency looks similar to that of a Deadly Nadder's as it contains lots of sparks and is bright orange.
The Boneknapper has a fairly regular looking fire. Similar to the Red Death, this dragon takes a deep breath before breathing a huge flowing stream of ashy fire. It does not appear to have extremely hot fire since the kids are able to survive very close to the fire during the Legend of the Boneknapper short. Also, the fire keeps coming up and down in waves.
A Buffalord's fire is uncontrollable, and can explode in an instant.
Three very similar species; the Gronckle, the Hotburple and the Catastrophic Quaken, share this powerful ability. Their fires are very unusual ones, more likely of shooting compressed magma or volcanic rocks. These dragons first eat rocks or metals that melt in their stomach, and regurgitate and spit them back out as balls of molten lava. The substances they use to melt these rocks is Heptane/Oxygen. These lava blasts are shot out with great force and can cause serious damage once they hit their target. Attempting to block one of these blasts with a shield would probably not work. Because the blasts have a fairly solid base the blast will plow through obstacles until it hits something hard enough to splatter the lava ball. This is seen in Riders of Berk episode 'Alvin and The Outcasts' when the dragons attack the outcasts, and proved to be effective even on big, strong foes such as the Screaming Death.
The Gronckle also has the ability to produce different types of lava by consuming different rocks. They can produce Gronckle Iron, lava of different colors, a transparent material, shiny balls of metals and even possess magnetic force in its body after eating certain rocks.
If a Gronckle ingests lots of small rocks or pebbles, it can quickly shoot them out before they completely melt and fuse with each other creating the regular lava blast. When it does this, the pebbles will be expelled in a rapid succession similar to a machine gun, though unlike a machine gun, these rocks will spread in a wide area. This attack is useful when attacking multiple foes at once, as seen on "Dragon Down".
See more information: Gallery: Gronckle (Franchise) in summary Dragons: Defenders of Berk.
Cavern Crashers are able to secrete a flammable green mucus from the craters on their backs. This slimy mucus becomes flammable when in contact with the air and is extremely sticky--virtually impossible to remove. They launch it onto their target with their body or tail before setting it ablaze. It can also set its tongue on fire and breathe out streams of green fire from its mouth like regular dragons.
Ironically, the Cavern Crasher is unable to secrete the slime under high temperatures, as the slime would be 'cooked'.
The Deadly Nadder's fire is very hot. It is said to be able to melt steel and turn a Viking into ash in seconds, and Bork claimed that Nadders had the hottest fire in the dragon world. Stormfly was able to burn an entire sea stack within seconds. The Nadder's fire is made up of magnesium, causing the fires look like torrents of concentrated sparkles. This results in the fire burning in a brilliant bright color with sparks flying off of it. Magnesium burns at around 5,600 degrees Fahrenheit. The Nadder seems to be able to breath fire without taking a deep, open mouthed to inhale, this seems to be a common ability among dragons. Theses dragons usually emit fires within relatively short period (in an instant) and the flames travel fast and straight, but they are actually capable of sustaining fires for long periods of time. Also, Nadders can sustain a low flame in their mouths to give out light and illuminate dark caves. However, due to its blind spot, they prefer to use their tail spines instead of fire.
The Eruptodon is able to shoot lava by regurgitating the lava that it eats.
The Flame Whipper breathes swirling explosions of fire.
Like the Monstrous Nightmare, they are capable of setting themselves on fire and glow in the dark at the same time. The fire that they emit burns hotter than the sun which is 27 million degrees Fahrenheit , which also means that the Fireworm's flames are as hot or hotter than the Deadly Nadder's Magnesium fire. According to Tuffnut, the Fireworm burns like ten suns.
The tiny Fireworms are not shown to have any fire breathing but their skin is incredibly hot. In Reign of Fireworms, tiny ones are known to set items on fire just by landing on them. They are shown to take some time--a few seconds or so--to heat up, when they do, they glow extremely brightly. This glow also seems to intensifies when they come closer to other Fireworms, and all their heat can be accumulated collectively.
One Fireworm however, Flashfright, can create a solar flap with powerful beats of its wings. This flare can temporarily disorient the sight of other dragons.
The Fireworm Queen is capable of breathing streams of hot fire (a similar type with the Monstrous Nightmare's fire; a bio-firecomb of topical and flammable gel) that spews out small fireworks. It is one of the most powerful fire breaths of all dragons. Their bio-firecomb, the fuel for its flame, can reignite Stoker Class dragons that cannot breathe fire. Their heat can also do so.
The Flame Whipper shoots swirling explosions of fire, aimed by its tongue for an increased accuracy.
As seen in The Serpent's Heir, the Foreverwing breathes large amounts of lava. This lava is powerful enough and in large enough amounts to destroy entire villages.
Unlike most dragons, which emit fire via their mouth, Gobsuckers release flammable gas through their rear behind. This ability makes it hard for anyone to sneak up on Gobsuckers as they will be attacked if they approach from behind.
This flames do not just serve the purpose of flames for a regular dragon, it also helps the dragon take off, gain speed and fly straight. Unique as this sounds, this flying mechanism poses some threats to the Gobsucker. Gobsuckers that run out of their shot limit will be unable to fly and as quoted from Gobber, "a downed dragon is a dead dragon". Furthermore, it may be difficult to attack opponents unless they are behind them.
The Grapple Grounder launches fireballs at its opponents and are said to create beautiful waves in the sky as they shoot.
The Hackatoo ejects average ball-shaped fireballs at its opponents.
The Hideous Zippleback has one of the most interesting ways of producing fire. Unlike most other dragon who breath in a flammable gas and then ignite it while exhaling, the Zippleback has one head that produces the gas and exhales it without igniting it. This gas is made up of Ammonium Nitrate mixed with Anhydrous Hydrazine, which has an explosive effect and produces a great deal of smoke. These chemicals produce a huge, flowing, green fog. The fog is said to have a noxious scent (this suggests it may be metabolic gas, like flatulence). It is bad enough to make anyone who breaths it in feel extremely nauseous. The gas, after being exhaled, is then lit by a spark from the other head.
The greatest benefit of this gas-based attack is that the green gas is diffuse at an incredibly fast rate, spreading throughout almost all areas. As such, the gas is able to seep into small, tight spaces, yet a single spark is still able to set of a chain reaction throughout the gas. As demonstrated by the Twins in Crash Course, they were the only ones who could destroy a wall of seemingly impenetrable wall of rocks as the gas seeped in between the rocks, and when ignited, exploded from within the wall of rocks.
In addition, in battles, the Zippleback has the ouroboros-like power to bite their own tails and set themselves on fire, taking on the form of a flaming wheel that knocks down their opponents like ten-pins.
As seen in the comic Dragon Down, both heads of a Zippleback are capable of releasing regular streams of fire. This fire looks somewhat similar to the fire used by the Red Death. Both streams of fire can merge together to form a larger ball of flames.
The Hobblegrunt shoots an Ethane expectorant. This suggests that this fire has a liquid consistency, similar to that of the Monstrous Nightmare. Though the Hobblegrunt is harder seen producing fire, it has been seen illuminating dark caves with with fire it sustains in its mouth.
The Moldruffle shoots out massive, powerful balls of fire. Moldruffles gather fire on the edges of their wings and tail, using their fan-like tail to strengthen the blazing flames.
In School of Dragons and Rise of Berk, they release powerful streams of blazing flames. They can either breath continuous streams of fire or shoot powerful balls of fire.
The Monstrous Nightmare has some of the most dangerous fire. It is made up of kerosene gel, so unlike other dragons who make fire with gas, they produce a green flammable gel and ignite it. When the Monstrous Nightmare breathes fire it is a sticky burning liquid; literally a bionic napalm. This fire is very destructive as it flows over houses and fields, but it actually doesn't seem to really be that hot as Hiccup is able to stand relatively close to it when he is being attacked by this fire. Nightmare out of flames. Because the fire is sticky, the Monstrous Nightmare often coats itself in it - another possible sign that the fire isn't all that hot, as Hookfang's fire coat causes discomfort but no real damage to people sitting on even a full burn. It should be noted that when using their firepower they are always seen spewing it over a target as oppose to blasting it, or when they blast it it is usually at short-range.
Hookfang can create a condensed ball of flame with greater destructive power by igniting himself and flying while breathing fire in circular motion.
The Night Fury's firepower consists of an explosive semi-solid mass of acetylene-oxygen flames. When at charging energy and shooting, high-pitched sound emit.
When it hits a target it explodes on impact. This allows it to kill almost all targets. The explosion is made up of a purple gaseous ring and a huge ball of fire at the center. The blast of plasma will explode even if it does not hit a target, because at high altitude, carbon dioxide is abundant and replaces the oxygen which creates the fire. The blast with no fire then explodes (as can be seen when Hiccup was riding Toothless for the first successful test drive). A Night Fury's flame can also be sustained for long periods of time, similar to a blow-torch. This is shown only when Toothless is preparing to rest or sleep, which he uses a sustained blowtorch-like flame to warm an area before resting there. Contrary to what the Vikings claim, Night Fury's fire probably burns hotter than the Deadly Nadder's. This is because acetylene and oxygen can burn at around 6,500 degrees Fahrenheit (hot enough to melt Tungsten, which has the highest melting point of all metals), while magnesium burns at around 5,600 degrees Fahrenheit. Though since no one has been able to capture, much less study a Night Fury this can be considered obsolete information. Toothless' acetylene-oxygen flame is actually ionized enough to become plasmoid (at least according to Hiccup). This would explain why it explodes on contact. Plasma works almost like a cross between a liquid and a gas. Interestingly it can exist a many temperatures (not just extreme heat).
Toothless has been seen to use smaller blasts just to blow things over or illuminate dark areas. These blasts do not seem to be as hot as his others, and it is very likely that he can control the relative strength and heat of his blasts. Toothless seems to refrain from using the higher temperature, more lethal blasts against enemies when he can help it. This is almost certainly due to Hiccup's influence on him. While in some cases Hiccup says that he has a limit of six shots, there is a lot of uncertainty about that, even if some sources, and even Hiccup himself in one episode states that his limit is 6, that fact might not be entirely true as even in original movie, in final fight, he was able to give more than 10 shots, with 7 full powered ones in really quick succession. or possibly, Night Furies recharge their shots very quickly, with weaker blasts recharging faster than others while more powerful blasts slower, but still rather fast. The shots might even recharge quick enough to give the Night Fury seemingly more shots than its shot limit allows.
The Night Fury is known to breathe a stream of normal fire, at least for supplementary uses.
A single Night Terror normally emit small streams of flames, but when they swarm together, the flames will combine and transform into a massive, powerful fireball.
Similar to the fire types of the Red Death and the Boneknapper, the Purple Death breathes a extremely large blast of regular fire. Their fire, however, does appear to exist in streams, encircled by a ring of fire.
The Raincutter has a truly unique fireball. Its fire is rain-resistant and is equally as powerful in rain, snow and sunny weather. However, it looks like a regular fireball.
The fire that the Razorwhip breathes can burn the flesh off a human from a hundred feet away. The bright blue color of the fire indicates how powerful its heat is. Their bright blue fire explodes on impact, leaving sparks flying. They can shoot many times rapidly and are incredibly precise.
In School of Dragons, however, it's fire is red in color.
The Red Death is a tremendous dragon, and its fire is equally massive. One blast incinerates the entire Berk fleets, and is released for long and the jet flame-like torrent along with gusts is powerful to destroy surroundings thanks to the dragon's tremendous lung capacities and exhaling power. It is a methane-based, billowing orange flame, and it has more ash than most other dragon flames, similar to pyroclastic blast of a volcano. It creates large amounts of black smoke, which makes it unique than any other dragon which don't create smoke. The Red Death inhales deeply before shooting fire. Directly after being ejected, the fire is a blue hue, but it quickly turns to orange. The fire in the film can go over half a mile according to The Art of How to Train Your Dragon, and the fire is shot in very similar manner as of a flamethrower. The dragon can cover the lack of agility and blind spots from faster or smaller enemies by flipping in midair in three-dimensional circular motions, resulting in engulfing the surrounding area and searing the targets, but it takes a little a longer to heat its gas then ignite it because of its tremendous lung capacities. It can also be powerful enough to destroy itself completely from within, if its fire is ignited by another smaller dragons.
The Rumblehorn expels long-ranged 'fire missiles' which initially start out as a white-hot fireball that quickly solidifies and turns to a warmer color before it ends up in a sooty stony material when it hits its target. It is also capable of breathing normal flames.
The Sand Wraith has a unique fire type. It ejects large balls of hardened sand surrounded by a coat of weak fire at its opponents. In School of Dragons, their fire appears to just be a rock that explodes into tiny bits of sand in mid-air.
The Screaming Death's fireballs can be launched either one at a time, or in rapid succession, much like a machine gun. Every time it launches a fireball, the frill on the Screaming Death's head flashes with flames and the fireballs themselves explode on impact in an incendiary fashion. Alone, these fireballs are also shown to be extremely powerful, as one of them was able to obliterate a tower in Berk in one shot. The Screaming Death is also capable of jetting out 'concentric rings of fire matching the round shape of mouth' which are identical to those used by the Whispering Death.
The Scuttleclaw can shoot green fire. School of Dragons states that is contains copper. In School of Dragons, the Scuttleclaw releases orange fireballs that explode in midair. Its fireballs appear both orange and green in color.
The Shellfire launches massive plasma-charged boulders from its mouth. Its firing range can be over a mile, and it can launch multiple boulders simultaneously.
Like many other dragons in Valka's Mountain, Shovelhelms have been trained to breathe fire to illuminate dark caves. This dragons sustains orange fire in its mouth to light up the caves
Singetails are able to launch scarlet fireballs from their mouths, gills and tails. Singetails are described to hurl balls of fire from their tails for long ranged attacks but prefer releasing jets of fire from their gills for close ranged attacks. This makes it virtually impossible to sneak up on a Singetail from the front, back and underneath, making it one of the most formidable fire-breathing dragon.
Though initially mistaken for marking their territory, Singetails set fire to foliage to signal for help from other Singetails.
Small Shadows spit balls of molten lava that can explode into orange fireworks.
The Smothering Smokebreath breathes a very hot fire. It is so hot it seems to be able to weld or melt hard metals together. It is possible that its temperature can rise up to 2750 degrees Fahrenheit ( 1510 degrees Celsius) as it is the melting point of steel. The hot air may function similarly to a hot air balloons fire.
The Smothering Smokebreath also emits large amounts of smoke from its skin to create a thick cloud of smoky fog to hide itself. They are often mistaken for ghosts and other supernatural creatures, such as a "Fog Monster". And according to the Riders of Berk DVD extra, "Dragon Tracker," the smoke is emitted from their skin much like the Monstrous Nightmare's fire jacket.
The Snafflefang breathes brightly-colored fire that can be used to illuminate dark caves.
Snaptrapper emits a Methane based mist. Since methane is a flammable gas it is assumed it can be set on fire in a similar manner to a Hideous Zippleback's gas.
A Snifflehunch is described to have a fire sneeze that can melt almost everything.
The Stormcutter shoots sustained, blazing torus of fire that forms a spiral.
As seen in a deleted scene for the second movie when Hiccup tries out some of Cloudjumper's fuel in his fire-sword, this fire is extremely powerful and difficult to control.
In School of Dragons, the fire, however, appears to burst into a blue or purple ball of flame on impact.
The Sword Stealer ejects powerful, streams of fire at its prey and enemies. Its fire emerges as a orange stream, with a white core, but turns green upon impact. This may indicate the presence of copper in the fire.
Terrible Terrors have a propane-based fire attack. This fire was described more as sniper bullets than flamethrowers. Their fire projects in long concentrated streams with deadly precision. Their accuracy in shooting is displayed by Sharpshot when he managed to fire three wooden targets mid-air when launched into the air.
Gobber says that you know when their about to strike when you hear a little hissing sound.
Thornridges eject powerful streams of green fire. It appears yellow when first released from its mouth, but later turns green. This may suggest the presence of copper in its fire that oxidizes and turns green.
The Threadtail is able to breathe orange fire to illuminate dark caves, but like that of a Snafflefang. Though unmentioned, the Threadtail probably has pin-point accuracy as it is a Strike Class dragon and they are known for their blazing accuracy.
In Rise of Berk, however, the Threadtail's flame appears to be small plumes of light green flame that slowly spread out.
Thunderclaws shoot average fire at its enemies, and its fire can be green sometimes in color or orange, like most flames.
The Thunderdrum has been shown to be able to produce blasts of fire that get bigger the farther they go. These blasts also travel at the speed of sound. The downside to this power is that it takes a lot out of a Thunderdrum to employ it, so it's not often used.
The Thunderpede emit what seems like a short stream of fire. Its fire is concentrated, but relatively weak and does not spread.
The Timberjack spits a fire similar to the Monstrous Nightmare's. It is slightly more sticky and globulous. It resembles burning embers and create beautiful glowing sparks. The Timberjack will occasionally secrete a few drops of its oil-based fire to burn the kindling wood it has chopped and collected. It can, then, fold its wings around the fire like a tent to warm itself, just as it's seen on the Book of Dragons short. Unlike other dragons, it is known to be able to attack more targets over a greater area with its fire nova in battle.
Like the Armorwing, the Triple Stryke shoots intense, concentrated blasts of fire that can blind its opponents. The fire is orange in color, and can still burn in wet and damp air.
The Typhoomerang flies in a scorching tornado of whirling fire. Typhoomerangs spiral into the air while scorching the ground, it is capable of creating a huge whirling burn mark with its fire. This is known as the 'Flaming Cyclone' by Dragons: Rise of Berk. This act is used in battle and courtship.
They have also been shown to be able to spin and wrap their wings around themselves in the air while flying before releasing a stream of fire that spins into a large combustive ball of fire. This was demonstrated by an angry blue wild Typhoomerang in The Eel Effect and was powerful enough to knock heavy dragons like Meatlug away in the air.
Typhoomerangs also possess the ability of leaving a trail of sparks as it flies, this ability was demonstrated by Torch in the Academy. The fire also acts like a fertilizer, because once the plants are burned by the fire, they will regrow and become more fertile. The fire of the Typhoomerang takes the shape of a flaming tornado, and is 'hollow', thus it can burn anything except for those that comes through it.
See more information: Gallery: Typhoomerang in summary Dragons: Race to the Edge.
The Whispering Death's fire takes the shape of rings of yellow fire and smoke because of a swirls ring cannon. It also has the ability to spit normal fire as seen when Whispering Deaths attack Bork and his girlfriend from below. However, its fire does not seem very hot as Gobber managed to block it using a wooden shield in Tunnel Vision. However, those were just adolescent Whispering Deaths and their fire may be weaker than an adult's.
The Windstriker can breathe fire into its mouth to illuminate caves.
However, in Rise of Berk, the Windstriker's fire is similar to that of a Monstrous Nightmare.
In Rise of Berk, the Windwalker shoots balls of fire.
The Bewilderbeast have ice blasts as their firepower which are the most powerful and destructive of all biological ranged attacks in the world of How to Train Your Dragon. They sucks up masses of water from the sea and stores it in pouches down its neck. The water is then likely highly pressurized, while the volumes combined heat is driven or wicked off. When it regurgitates the water, it returns to a normal pressure and experiences a drastic drop in temperature. When it hits its target, it freezes, mid-splash. This causes it to form its spiky shape, as the ice expands. The Bewilderbeast can also exhale a small, frosty breath.
Their icy blasts are able to partly destroy a village and huge forts. Bewilderbeasts mainly use their ice to construct cooling habitats for dragons to live in. This results in a large spiked mass of ice when viewed from the outside. However, on the inside, their ice can sustain the growth of plants and formation of large water bodies while keeping the temperature in it low, as shown in Valka's Mountain.
The Groncicle freezes its targets with exploding ice attacks of liquid nitrogen. Liquid nitrogen can reach temperatures up to -321 degrees Fahrenheit (-196 degrees Celsius). This causes the Groncicle to have a very low body temperature, causing the water around to freeze as it swims.
In contrast to School of Dragons, Dragons: Rise of Berk claims that Prickleboggles have a cool, icy blast. Considering they have icy breath, it is possible their healing breath is also cold to soothe the pain and inflammation of injuries, like putting an ice pack on the wound, along with being medicinal. But this is mere speculation.
The Scauldron's "fire" is not fire and therefore unusual, though since these dragons live in the sea, they can't use fire anyway. These dragons first swallow a gallons of water, heat it in their stomach, and then fires the water in a scalding jet at its prey/victim. The dragon gets its name from this ability. The water it spits is extremely hot and will usually finish off it's prey/victim with a single shot. Gobber claims it will melt the flesh right off your bones.
The Scauldon may or may not be able to demonstrate the ability to breathe fire, as some Vikings have smelled the flammable gas that comes before flames.
The Shivertooth fires frost. It is released in a thick stream and appears to have many snow or frost particles in it.
Though Dragons: Rise of Berk previously mentioned that Snifflehunches have a fire sneeze, one individual, Sneezlehunch, is described to have an icy sneeze after dwelling in icy climates.
The Snow Wraith is able to shoot frost in quick, rapid fusillades at numerous targets. Their frost is emitted in thick, concentrated blasts that seem to glow as it emerges from the dragons' mouth. This attack is exceptionally powerful and destructive, as it can easily blast a Viking out of his spot. The Snow Wraith can eject these blasts at an immense speed.
As a Strike Class dragon, this dragon hardly misses. These blasts have been known to eject in three charges in School of Dragons.
The Tide Glider sprays water which is contaminated with it's saliva which can heal wounds. The water appears misty and has many droplets of water. A Tide Glider is able to shoot both streams of water or concentrated balls of them.
According to Dragons: Rise of Berk, the Windgnasher has an icy blast and even has a "blizzard attack," a very powerful icy blast with whirling winds.
The Woolly Howl shoots hailstones, shown in School of Dragons to be sustained in a spinning spiral shaped blast or a shower of hail.
Being in the Strike Class, it can fire its highly explosive Ice blasts from a far distance with a lot power and pin-point accuracy. Like other Strike Class dragons, the Woolly Howl can control the force of its blasts.
Their acid is green, gurgling, sticky, and melts through most substances. The Changewing can spray large amounts of acid at a time. It is highly dangerous and is shown to eat through huge wooden trees in seconds, however it cannot destroy metal. The dragon appears to be mostly immune to its own acid as it can walk through it without showing any signs of pain. But in the short Book of Dragons, they appear to breathe fire. However, this could be added because of comical purposes. The game, Dragons: Rise of Berk, states that this acid is strong enough to burn through wood, rock and even Vikings. It is later shown that Changewing acid can melt dragon-proof metals. The acid is also highly viscous, and can stay intact underwater.
In addition to its fire produced by its rear end, this dragon also has a powerful acid blast that can eliminate enemies quickly. However, this is its secondary fire type and Gobsuckers rely more on their fire.
The Sliquifier can use it's speed to churn up a powerful acid stream. This is unusual, since most dragons that fire acid has a ball-like shape that has a direct impact on targets. The Sliquifier's acid is stronger when the dragon moves faster at the point of release.
The Snaptrapper shoots a type of acid that can melt through metal. They appear as large streams of green acid.
The Submaripper shoots exploding balls of acid which is usually shot within a close range, but has a result of forceful power.
The Sweet Death fires acid while it usually stays put in one area. Their acid is dark orange or brown. When fired, their acid usually comes out in a concentrated stream before bursting into many droplets.
Along with it's watery firepower, the Tide Glider can shoot several balls of acid at a time to clear it's path. They appear as large balls of green acid.
The Grapple Grounder can shoot a light-blue pulse ball, possibly of electricity or plasma or a sort. It can shoot multiple of the blue orbs at a time, but at a sacrifice of size. The balls have a somewhat magnetic field, drawing towards larger objects than it (ie, opponents or victims), however the more decreased the size the stronger the force is. This information could also infer it might be electromagnetic. If a Grapple Grounder takes a deep enough breath, or charges it long enough, the fire will come out as a big blackish sphere that explodes impressively upon impact, almost fatal. Its bomb contains Magnesium gel.
The Seashocker, utilizing the ability to produce bioelectricity, can attack and stun targets at mid-ranges with highly-charged electron waves or currents. They bite their prey with their electrical bite, stunning and paralyzing them. It also uses its electrical ability as a defense mechanism from predators. Seashocker can direct its electricity from one head to the other and this results in a bright sparks produced in between their heads, like that of a Wimshurst machine. Also, Seashockers are able to generate such a large field of electricity that it can knock many large Scauldrons away in water.
The Shockjaw can shoot an electrical stream of bio-electricity. It first starts up as a gentle jolt, but as it travels, it is converted into a lethal bolt. It is described to feel 'up-close and personal'.
The Skrill shoots an electrical white fire, known as a lightning blast, as its body crackles with static electricity. As soon as the dragon begins to breathe its lightning-like breath, the electricity arches through its mouth and sparks along gasses that form the body of the blast.
It is one of the most unique types of blasts since it contains both an extremely hot fire and a powerful electrical current. It also creates strong ozone smell, due to the air ionization during discharge. Though the huge amount of electricity is fatal, Snotlout and Dagur were hit by the Skrill without dying or passing out like Hiccup when he was hit by actual lightning. This may suggest that the lightning that Skrills produce are of a lower voltage than actual lightning. Or it could just be the size and power of different blasts. For example, the Skrill can shoot lightning powerful enough to bring down an iceberg.
Though most Skrills' flames appear white or blue, in Rise of Berk, Hunterbolt ejects orange, yellow lightning from its mouth. He also releases waves of orange electric pulses around it and his body starts to emit light. Unlike other Skrills that have to draw lightning to themselves before absorbing it and striking, Hunterbolt can directly control lightning. Occasionally, lightning strikes at a specific spot of his habitat.
see more information: Gallery: Skrill in summary Dragons: Defenders of Berk; Dragons: Race to the Edge and Book of Dragons.
Just like the Skrill, the Windwalker is covered in lighting and is able to shoot it at its opponents.
The Bewilderbeast is known to produce ultrasonic sounds to control the minds of other dragons. The only dragons immune to it are baby dragons as they 'listen to no one'.
The Death Song uses a siren like sound to lure its prey to a remote island. The Death Song has an extra-cervical vertebrate. When the Death Song calls, its extra vertebrae expand into its frills, and its song is able to be projected to specific targets up to a mile away. Thunderdrums are the only dragons immune to it as they are hard of hearing. Though it is not known to be able to knock out prey or defend from a distance, like fire.
The Mudraker produces sonic sounds that travels through water in fast speeds and causes the water to form into massive, powerful waves. In School of Dragons, they appear as waves of blue rings.
The Screaming Death is able to produce a loud noise that disorients dragons, causing them to lose focus and feel very uncomfortable.
The Shadow Wing can produce a loud, powerful roar that can disorient humans and dragons, as well as affecting its surroundings. The roar is also a signal for Small Shadows to attach to its wings to form the dragon's iconic bomber formation.
The Thunderdrum delivers a sonic blast that is deadly at close range. Thunderdrum lets out sonic blasts so loud it's been known to shatter glass and crack teeth. The blast ripples through the air and can push obstacles and enemies back at great speed. It is, as mentioned earlier, really only severely dangerous at close range, but it remains a devastating attack all the same. At the very least, a normal person's eardrums run the risk of rupturing. It has proven strong enough to break off the main mast of a ship and send a horde of wild boars flying. It is theoretically possible that the sonic roar would be more effective against targets that are underwater, since sound travels better through water, which makes sense as the Thunderdrum is amphibious. According to the legends, the Thunderdrum gets this power from Thor himself. It is capable of delivering a thunderous sonic blast that can be heard for miles. Thunderdrum babies hatch from their shells by making a sky-rattling sonic boom. Their sonic roar is even capable of reflecting small projectiles making it both a defensive and offensive weapon.
Some dragons seem to be immune to its roar or only slightly affected by it such as the Whispering Death. However, by focusing its sound into a more concentrated form, the Thunderdrum can release a sonic blast than can do more physical damage. As shown with Stoick's Dragon Thornado, this can either knock down juvenile Whispering Deaths, or even briefly stun a Screaming Death. When several Thunderdrums cooperate, the combined blast is powerful enough to knock off many wild dragons instantly.
Boneknappers have a thunderous sonic roar, but this requires it to have all of the bones in its armor. It can also be used as a mating call.
The Windstriker heats air up in their body, then blasts it at its enemies. Its super heated air is one of the most powerful strike of all dragons. These blows are hot enough to set their opponents on fire.
The tail of a Flame Whipper contains an acidic poison that can paralyze for a short while.
The Threadtail has the ability to secrete poisons from their skin, which is extremely lethal to animals and humans. This ability mimics that of a poison arrow dart frog. However, the Threadtail is allergic to the poison and have to roll around in Dragonberry bushes to relieve the itch.
The Death Song shoots amber-like substances that solidifies rapidly to trap its prey. This substance appears to be shiny and is normally seen as large orange blobs with dragons and unsuspecting prey trapped in it. This amber is so strong that dragons, including a Night Fury, could not break the solid substance with its jaws. This substance can only be penetrated by flame as it causes it to melt into a liquid.
The Flightmare shoots a toxic glowing blue mist that paralyses its victims just long enough for it to finish them off. Rather than freezing a target immediately, the initial paralysis seems to be caused by "stiffening" the skin, making it harder for the muscles to work. As the skin absorbs the mist, the muscles themselves are paralyzed. The victims appear "shiny" until the mist wears off, possibly because of some elements of the mist are not absorbed by the skin and have to dry off.
However, in Dragon: Rise of Berk, Ruffnut's Trancemare can emit a purplish mist. It starts out as regular purple mist, before a powerful, purple stream of paralyzing liquid is ejected from its mouth.
Prickleboggles can inflict minor damage with their blast, however their blasts are also known to have impressive healing properties. Their blasts consist of small purple particles suspended in purple mist. They use these abilities to cure other dragons and they, in return, stay loyal to the Prickleboggle. They are able to calm and relieve others in chaos. With these talents, Prickleboggles have many close allies and bonds with others.
Submarippers vomit the shipwrecks they have ingested, spraying their targets with harpoon-studded debris.
Similar to the Flightmare, a Threadtail individual, Mildew's Strain, can produce a purple mist. This mist leaves shimmery purple puddles that appear to be of the same shade as the Dragonberry bushes Threadtails are fond of.
Fire or Attack Combinations
In Heather Report, Part 2, Astrid and Snotlout combined the attacks of their dragons. Hookfang would set himself on fire (everything except his head and part of his neck to avoid toasting his rider, apparently) and fly across Stormfly's path right as she launched her spikes. When timed correctly, the spikes would set on fire as they passed through the edges of the fie jacket, making it even more important to get out of the way.
Monstrous Nightmare and Fireworm Queen
When both these formidable dragons come together, they start to combine firepower. The result is a gigantic stream of fire set ablaze of an incredibly high temperature, and when fanned out, the flames are capable of incinerating everything in front of them.
In Live and Let Fly, Hiccup and Stoick fought against an armada of outcast-ships, and Hiccup noticed that Toothless's plasma burst combined with Thornado's sonic roar to make a fireworks display of purple sparks. He called it a "plasma scatter-shot".
Night Fury and Skrill
In View to a Skrill, Part 1 and View to a Skrill, Part 2 Toothless fires a Plasma Blast at the Frozen Skrill and then the Skrill fires back with its lightning. The reaction causes a small concentrated ball of plasma and electricity of a high voltage, before this small 'nebula explosion' collapses inwards due to the pressure and heat. This sends out a circular shock wave outwards, creating a purple plasma lightning explosion.
This blast is extremely powerful as it is was shown to be able to knock out up to three dragons in the air.
Hideous Zippleback and Deadly Nadder
In the second film, Barf and Belch have been seen to release lots of gas while Stormfly ignites it with her fire. This is rather useful as Zippleback is highly flammable and all it takes is a single spark to ignite it. With a Nadder's hot magnesium flame that is believed to be one of the hottest flames produced by a dragon, this causes a thick and hot stream of fire hot enough to melt metals.
In How to Train Your Dragon 2, many dragons fired their shots up into the sky simultaneously. This resulted in a gigantic orange cloud of fire and smoke in the air. Sparks fly out of this mass of fire and it releases a circular shock wave of smoke and a large explosion.
The dragons' fire included in this explosion are: Night Fury, Deadly Nadder, Monstrous Nightmare, Gronckle, Hideous Zippleback, Hotburple, Rumblehorn, Stormcutter, Terrible Terror, Shovelhelm, Hobblegrunt, Snifflehunch, Threadtail, Thornridge, Thunderclaw, Scuttleclaw, Raincutter, Snafflefang, Windgnasher, Windstriker, and four other Unknown Dragons. There may be other dragons that contributed to the blast which were not shown in the film and there may be a possibility that there were non-fire breathing dragons.
Eels have been shown to affect dragons fire differently. For a Night Fury, for instance, it creates a red plasma shot that explodes on impact and it increases the shot limit. This comes at the cost of the dragon getting Eel Pox (which is why most dragons avoid eels). Typhoomerangs on the other hand can consume eels to increase their shot limit and fire power without contracting the disease.
Non-Projectiles / Special Weapons / Unique Attacks
Used mainly by the Deadly Nadder and the Razorwhip and sometimes by the Whispering Death and the Screaming Death. It was used for additional purposes and poisonous attack.
Used by the Gronckle. When provoked, Gronckles can inhale deeply, and the bumps on their body blast off in every direction.
Used by the Gronckle, the Hotburple, the Snafflefang, and the Red Death, they get close to the targets and beat them using the tail tips. It is very powerful and can knock over several Vikings at once. Their tail usually has spikes or bumps on it.
Used by the Monstrous Nightmare and the Moldruffle. They can set their bodies on fire to cause conflagrations on buildings or forests.
Used by some dragons that can use their tail to whip enemies.
Used by the Skrill and the Windwalker. They can put their bodies with electricity, the effects may cause storms in the sky.
Due to having large lung capacities, the Red Death and the Screaming Death can cause strong inhaling air currents that are powerful enough to make extremely fast-flying targets, such as Night Furies or Deadly Nadders, hover and even be drawn backwards.
Used by the Speed stinger. It uses the barbed end of its tail to inject poison to its victims that paralyze them temporarily.
This is also used by the Triple Stryke, which has 3 barbed tails that bind together to form one. A sting from the first one numbs its target, the second disorients them with mild hallucinogens and the third causes a burning pain.
Used by the Changewing, mostly for defensive purposes. It can also be used to sneak on prey a strategical attack or defending its territory.
Used by the Seashocker, they can paralyze their victims through their bite, using a powerful electrical discharge.
Used by the Snaptrapper and the Sweet Death. The Snaptrapper can produce different smells for different purposes. If it wants to attract prey it produces the tempting smell of chocolate. If it wants to repel other dragons or Vikings it produces a noxious smell of putrefaction that scares off even the most starving Titan Wing. Similarly the Sweet Death buries itself underground and uses its sweet scented tongue to attract prey.
Used by the Cavern Crasher. The Cavern Crasher is able to secrete flammable mucus from its body. It launches out the mucus from its tail or body onto other objects before setting them alight with its fire.