Monstrous Nightmare (Franchise)

"And then, there's the Monstrous Nightmare. Only the best Vikings go after those. They have this nasty habit of setting themselves on fire."

- Hiccup introducing the Monstrous Nightmare

The Monstrous Nightmare is a large Stoker Class dragon that first appeared in How to Train Your Dragon.

Official Description
"No dragon is more ferocious, or feared than the Monstrous Nightmare. This gigantic dragon has a long, snake-like neck and tail, and is covered in red scales and long sharp spines. The Nightmare's gigantic head and mouth can swallow Vikings whole. It is highly aggressive, and will never run from a fight. Its fire is thick and sticky, clinging to walls and running down hills like a flaming river. The Nightmare also has a nasty habit of setting itself on fire."

- Dragonpedia

"This red-and-black creature with a huge wing span produces a kerosene gel fire. “He is the most dragony of the dragons, but the thing that we like is that he is the most showy. We always felt he was the Mick Jagger of dragons. He’s a natural-born performer who comes out engulfed in flames because they can set themselves on fire."

- Chris Sanders

"A stubborn and tenacious Stoker Class Dragon. Look out for its Fire Jacket: It covers itself in flames when attacking! The Monstrous Nightmare attacks its foes with powerful streams of fire."

- Dragons: Rise of Berk

"Monstrous Nightmares are known as some of the most ferocious and aggressive dragons. As a member of the Stoker Class, these dragons are hot-headed and have a particularly strong ability to breathe fire. Monstrous Nightmares are known for setting their entire body on fire. These dragons are incredibly fearsome and can also fly at a high speed. These creatures are usually either purple or scarlet in color with snake-like features. Sly and sneaky, Monstrous Nightmares also use their claw-tipped wings to crawl along the ground. Their intimidating glowing eyes strike fear to those who come near. While these dragons might appear intimidating at first, it is important to remember that they can be trained. All that these belligerent dragons need is a firm hand and a confident trainer!"

- School of Dragons Website

"No dragon is more ferocious, or feared than the Monstrous Nightmare. This massive dragon is covered in red scales and long sharp spines. The Nightmare's gigantic mouth can swallow Vikings whole."

- DreamWorks Dragons: Wild Skies

Development
Described to be the very embodiment of the typical 'western dragon' of the film, the Nightmare is said to be the most 'classic'. It is compared to being 'half lizard and half bat', since it could walk on its wings. Nightmares also have snake-like attributes in their behavior.

Character Designer Nico Marlet created an 'intimidating flame motif into its shape patterns' and made sure to give it plenty of teeth--ninety seven, in fact. Nico's original concept of the Nightmare, titled Monstrous, features an even more stereotypical dragon. It has four legs, a hunched back, and rounded belly. Previously, the Nightmare only had one set of wings, but a second set was added to further distinguish it from the 'classic' dragon.

"The designers wanted to add translucency to them to give a whole other level of detail when backlit."

- Sabrina Riegel, Head of Surfacing

Modelling the wings required the consultation of an ornithologist, as there was heavy emphasis on bird anatomy, and the wings' appearance was a major focus in the film.

The animation team decided to give this dragon a somewhat vicious, liquid-based fire that could 'stick onto surfaces and roll off and splash'. The power of CGI had given them a chance to stretch the limits of film making, and Dean described that they wanted to move away from the usual propane-based fire, which is used in live-action films as it is easier to extinguish. Thus, the team gained inspiration from fire rising against the ceiling, turned the video upside-down, and gave the Nightmare's fire 'some gravity', which meant that the fire was fluid-based, not oxygen-based.

Egg
The Monstrous Nightmare eggs have a surface that looks like they were made of cloth or leather folded together, with a spotted pattern on the base. Its colors vary and they match the colors of the dragon to be born. In School of Dragons, however, they are brown and smooth with a pattern similar to tree bark.

Hatchling to Adult
Monstrous Nightmares come in many different colors such as purple, blue, scarlet, or green and possesses a long, snakelike neck and tail. Unlike some other breeds of dragon, it has no forelegs, and its ground-based locomotion is similar to that of Pterosaurs, except that it has a lower profile due to its sprawled wings; it can use its claw-tipped wings to "crawl" along the floor. Their horns might be used as a visual display and in defense, but the swept back position of the horns means it is unlikely to use them in combat. In most pieces of media, this dragon posesses two rows of spikes on it's back, but in Rise of Berk the spikes are replaced by two sails. Its stripe skin patterns seem to mimic that of a tiger's. Find more information on this here. The Monstrous Nightmare is 60 feet long, has a wingspan of 68 feet and weighed about 5,000 lbs.

In the How to Train Your Dragon Live Spectacular, the Monstrous Nightmare has front legs and walks quadrupedally. It also lacks the tall, wavy spines running down its back. Other characteristics such as the head horns and coloration are the same as other parts of the Franchise. The differences may be due to the difficulty engineering a live action animatronic puppet.

Titan Wing
In "Total Nightmare", the first Titan Wing Monstrous Nightmare was seen. While aging, they can lose their stripes to have black spots, similar to the leopard. When they are fully grown and gain barbels, some of them change color when they achieve Titan Wing age. In Rise of Berk the sails they posessed as adults become rows of separate spikes. Once they have reached this stage they grow much longer and may gain spots in more striking colors. With age, Monstrous Nightmares seem to also grow beard-like appendages under their chin as a sign of age, as seen by Hookfang in How to Train Your Dragon 2. Though this might mean that some of the same species of Monstrous Nightmares could age quite differently than others.

Abilities
The Monstrous Nightmare is one of the strongest and most formidable dragons with a wide variety of abilities.

Monstrous Nightmare Fire Types
Monstrous Nightmares breathe an organic Kerosene Gel, which can be hotter than a usual flame and more powerful as well. Their fire is hot enough to burn down a tree in a few seconds.

Its signature attack is known as the "Fire Jacket" or "Fire Burst". This ability makes it engulf itself in flames (according to Snotlout, by igniting the spit it coats itself in prematurely), resulting in an intimidating, offensive and defensive maneuver similar in appearance to napalm or other gel-based incendiaries. They are able to set any part of their body on fire shown they can do even on their horns. They are also able to fire off a larger and more powerful fire blast whilst doing this as shown in the first movie and School of Dragons. It also said that Fire Jacket ability also make the Monstrous Nightmare while running downhill makes it appear like flaming river possible spreading the fire on the tall grass.

In the Dragons: Race to the Edge episode "Dire Straits", Hookfang is shown to shoot fire bolts underwater, although Gobber mentions dragons getting their head wet will momentarily make them unable to breathe fire. Monstrous Nightmares have the ability to Fire Burst to make their body temperature stay heated as they can dry off from being wet. This might be possible mistake from the Creators of Dragons: Race to the Edge as they made Toothless and Stormfly shoot fire underwater as well.

The natural form of the Monstrous Nightmare's kerosene gel was shown to be green in color. It coats the dragon's hide, allowing a Nightmare to 'flame up'. The gel is also slimy, being easy to rub against a platform. It occurs in large enough quantity for a Viking to collect and store for other uses. The gel is highly flammable and is one of the tools to efficiently penetrate the Death Song's amber substance. Nightmare gel also appears to be water-soluble, as evidenced in "Dire Straits" when Fishlegs and the Twins experiment what might eat through dragon-proof chains underwater. Nightmare gel is not a good option.

Senses
The Monstrous Nightmare has also been observed to have a well-developed sense of smell, as Hookfang was able to find Snotlout's scent in "Defiant One" over a day as he was separated from the ocean. However, it is unknown how strong is their sense of smell exactly.

Strength and Combat
Monstrous Nightmares are among the most physically powerful dragons as they can send heavy Vikings far distances by using their tail and can send a Gronckle flying full speed with an extra heavy weight Viking riding on them by hitting with their wings. Monstrous Nightmares have even shown to be able to easily crush the Mangler that Hiccup had invented to use to capture Toothless with one stomp of their feet in How to Train Your Dragon.

Monstrous Nightmares are among the most well-armed dragons, for they are able to use their jaws, claws, tail and horns as formidable weapons in battle.

Their neck muscles are very strong, as they are able to carry heavy Vikings on their necks, sometimes with an extra weight of a teen Viking with no sign of any struggle, with a weapon, and with a saddle. Hookfang has proven for his kind that Monstrous Nightmares are able to toss an entire Night Fury with his mouth, despite having a toothache. Monstrous Nightmares, as proven by Hookfang, that they're able to lift the entire weight of a Fireworm Queen or can carry a large amount of weight. In "Snow Way Out", Hookfang is able to carry two of the Snow Wraiths, one in a cage, and another in a net with just his feet, and with the extra weight of Snotlout with no sign of trouble.

They are quite powerful fighters, as they can show off their combat ability to try to fight off a Night Fury, just like how Hookfang has demonstrated to put up a good fight against Toothless twice, although the fight was broken up or unfinished both times. It said that Monstrous Nightmares will never run from a fight, but it is possible that if this dragon knows it can't win against a really powerful opponent, it will flee.

Speed and Agility
Nightmares have been shown to be quite fast, both on land, in water and in the air. Hookfang was able to catch up with Toothless in "Thawfest", though it is very well possible that this was the result of Snotlout's training, and that a wild Nightmare isn't capable of this. Nightmares on land have been observed as fast runners while in a straight line, although they have trouble making turns. They are agile and fast fliers as they are able to go around trees and able to dodge many arrows, as demonstrated by Hookfang and Fanghook also Nightmares are able to make flip in the air as well.

Swimming
Monstrous Nightmares have also been observed to be fast and agile swimmers, as Hookfang proved. It's unknown how long they can stay underwater, but it is possible Hookfang would have been able to hold his breath longer if he hadn't been burdened by Snotlout.

Climbing
Monstrous Nightmares are excellent climbers on both chains and many different types of terrain shown to be able to climb mountains and Viking catapult towers as shown in the first film. They can also climb against stone/metal walls while running quickly.

Intelligence
Monstrous Nightmares have shown to have very intelligent if wanted too such as if they get the good respect that they deserve from their owners, they can learn great skills over a day as demonstrated by Fanghook. But if they don't get sufficient respect from their owners they will sometimes to prank them and unexpectedly outsmart them, just like how Hookfang has demonstrated many times on Snotlout. Its also possible that Astrid's Monstrous Nightmare have shown that they are able to understand that the punch she gave to the Monstrous Nightmare was use as distraction to be able to save her life later from thrown off the cliff.

Wing Blast
They have a hidden ability that Astrid discovered is known as a Wing Blast, when she temporarily became Hookfang's rider in "A Tale of Two Dragons". They use their large, powerful wings to create a blast of wind that is so strong, it can even blow a fully-grown Hideous Zippleback to the ground. It's even able to push back the weight of gronckle with the extra weight of a heavy rider while pulling off a dragon root but unable to pull out the root from the ground.

Endurance and Stamina
Monstrous Nightmares have high stamina and endurance, as was proven multiple times in the series.

A Monstrous Nightmare from the first film is shown to take the raid of attacks from Stoick from his large hammer or with his bare hands though Hookfang even proved to take the attacks from Toothless the Night Fury with addition he even took hit from Astrid hammer. Their durable skin is able to bounce an arrow off their skin and the skin on their head is shown to be quite durable in the "Defiant One" though it is quite possible that a larger arrow that is such as one from Dagur's crossbow might be powerful enough to get through the skin of Nightmare as Hiccup resisted Dagur to do kill wild Nightmare. They are able to endure Deadly Nadder magnesium blast that is very powerful enough to melt solid rocks but Hookfang was using their wings as a shield and are able to whist and can endure a very powerful lighting blast from wild Skrill to continue to fly.

Monstrous Nightmare has great stamina as they are able to travel long distances. In the first film, Hookfang was able to run the whole arena when releasing from his cage and chase his prey such as Hiccup, Astrid, and an addition of fight with Toothless though he still has shown to be a great condition to back off from the fight. Though Monstrous Nightmares never really shown to be quite exhausted as many dragons do have great stamina on their side though if they do being pushed to hard to from traveling full speed they can show to be exhausted though they still can fly fast as Hookfang shown but they can get very sick and lose the ability to produce fire and if that happens they will get weaker and weaker until they die.

Kerosene Saliva
According to the Dragonpedia, young Monstrous Nightmares drool excessively as babies, as many species do. However, that drool contains the kerosene gel that coats the scales and makes it very volatile.

In the game, Dragons: Rise of Berk, the description for Sven's Nightmare indicates that it "blasts poison instead of flame". It is widely thought this is an error on the part of the game, as Sven's Nightmare breathes fire in Dragons: Race to the Edge. However, it might be possible to consider this individual is 'spitting' kerosene-laden saliva. Kerosene is a toxic substance.

Jaw Expanding and Jaw Strength
Like snakes, Monstrous Nightmare is stated open their jaws wide enough to swallow a full grown Viking whole, which is shown when Hookfang is able to fit Snotlout's torso in his mouth.

According to Dragons: Rise of Berk, Monstrous Nightmares are able to chew through anything, even the cages that they are trapped in. If this is possible, it might take some time for Monstrous Nightmares to break out from dragon proof metal cages.

Hunting and Fishing
According to Dragonpedia, as hatchlings, they are skilled hunters.

Just like modern carnivores, Monstrous Nightmares seem to chase their prey down with their great stamina to tired them out to attack. As shown from Fanghook before being tamed he was hunting wild boar as he was chasing down his prey on land. They could hunt as solitary or can even possible as the pack if they hunted bigger if needed.

With their swimming ability to hold their breath for a certain amount of time they can fish as they show of the pictures of the book that can hooked the fish on their spines. And they use that to keep their fish warm to eat another time. They might use their spines to hold more fish to feed their youngsters at their nest as they can store an amount of fish in their mouth and more on their spines.

Titan Wing Abilities
A Titan Wing Monstrous Nightmare is fully grown form that has shown to enhanced physical attributes and abilities that make them stronger in strength and bulk.

Also, their range of fire is increased so targets can be hit at a further distance. Their fire breath seems to be quite brighter then average size Nightmare. Though it hasn't shown if they can use their fire burst as the Titan Nightmare hasn't shown this ability though if not able to quite possible loose this attribute for their larger and more fire power of their flamethrower.

Titan Wing Nightmares are proven to be extremely strong able to toss away heavy dragons with its head that weighed over 5000 lbs without a struggle over their body or even knocking a dragon off in the air by using their tail. Though the Titan Monstrous Nightmare easily can defeat an adult Nightmare like Hookfang could be possible to give Toothless harder time for combat as Toothless fought Hookfang twice the Titan Monstrous Nightmare will be tougher challenger the proven to be more determination.

They have a really durable body than average Nightmare which can take average blasts from different dragons, or even smashing into trees and other terrains by traveling at great speed. Quite possible took some attacks from Hookfang before Snotlout had arrived for the final time.

Titan Nightmare has a higher stamina and speed than a normal Monstrous Nightmare. As proven to be fast enough to catch up to Hookfang who has been enhancing his speed for the past few years with hard training that can reach to close to Hookfang's tail. As the Titan Nightmare also proven to have greater stamina then Hookfang, as it might be possible belief that has battle Hookfang right before Snotlout, had return one last time seeing Hookfang on the ground that he appears to be out of breath as the Titan Nightmare was ready to continue the fight no matter. As Titan Nightmare even show their determination will be greater than average Nightmare as they willing to continue a fight and fly away in great speed.

Though they are 'fully' grown and as big as their species can get as a Titan Wing, there may still have the hidden ability of the wing blast as more powerful than average Nightmare.

However, this also causes maneuvering difficult, due to being heavier and possible the long tail, this means it can't stop itself as quickly and can't make tight turns. Though like average monstrous nightmares they can still swing their tail to whip.

Flame Loss
The true weakness of this dragon is losing their flame as well as their fire burst protects them from hypothermia that could make this dragon become very weak and they can easily die from this. According to Fishlegs they can lose their Fire Burst from old age, exhaustion or injuries. Symptoms include flaky skin, pale coloration and inability to light up. Although Hookfang was shown to still be able to fly high, he quickly lost altitude.

Their other weakness is tying up their snout that they won't be able to use their Fire Burst but they are able to still fight back.

Turning in Flight
Due to a Monstrous Nightmare's long tail, they can't pull up in time when charging in a full speed dive. They are very fast when running in straight line but bad at making turns as stated by Ruffnut.

Also, Titan Wing Monstrous Nightmares are unable to maneuver as quickly as younger ones and have difficulty making sharp turns while flying. Their size hinders their mobility of flying and they can be taken down by younger Nightmares.

Behavior and Personality
By nature, the Monstrous Nightmare is fearless and proud. They are some of the strongest dragons around and they know it. Monstrous Nightmares are very aggressive. In battle, they are said to be the first to arrive and last to leave.

Incendiary in temperament and short on patience, Monstrous Nightmares would incinerate first and think second, according to the Dragonpedia.

In "Heather Report, Part 2", Snotlout revealed that the Monstrous Nightmare enjoys its horns being pinned to the ground and Astrid was able to tame one by doing so. This dragon later returned and saved her.

According to Gobber the Belch, the best way to engage a Nightmare is to clamp its mouth shut, leaving it unable to open its enormous jaws, much like a crocodile (however, the rest of the dragon is free to do whatever it wants). They are also fast in a straight line, but not so good with turns according to Astrid Hofferson

Despite their name, Monstrous Nightmares are known to have a softer side. In DreamWorks Dragons: Wild Skies, they love the smell of scented flowers. In "Dragon Down", Hookfang at least is known to be fond of eating rats so it is possible that all Monstrous Nightmares like eating rats. At several points of Dragons: Riders of Berk, Hookfang occasionally dozed off or was distracted by leaf, chasing a seagull, or anything else, sometimes they don't even notice that an object as big as a rider falling off them. Being a hot-headed, feisty dragon, they will attack anyone in its way if spooked. Every time Monstrous Nightmares attempt to fight off Toothless, they are blinded by their aggressiveness that Night Furies are a far bigger threat than they think.

While other babies, which drool regularly, baby Nightmares are much different as they slobber packs of punch that their kerosene gel composition makes it akin to lighter fluid.

When born, baby Monstrous Nightmares hatch fast and fiery. They are quick to be separated from the rest of the litter and assert their independence within minutes of their birth, but this hasn't been confirmed as shown on the Dragon Breeding Island when some baby Nightmares were still with their parents. They were shown to be eager to join their parents when setting off the return migration to Berk but like all the others baby dragons, they are unable to fly well due to their small wing and the strong winds that are preventing them to take off.

It was revealed in the episode "Total Nightmare", that female Monstrous Nightmares are able to call males that aren't her mate, but another individual of their kind. As Hookfang was shown to help a female dragon of his kind to defend her eggs from Titan Wing Monstrous Nightmare. Male Monstrous Nightmares are shown to be determined to answer this distressed call.

Their mating habits are similar to a lion's, as seen in Total Nightmare; rival Monstrous Nightmares who are fighting for a mate will want to destroy the predecessor's eggs, much like a new alpha male wanting to destroy the previous alpha's cubs.

These dragons are also extremely territorial, protecting their young and helping other individuals of the same kind. In "Total Nightmare", Hookfang was helped a female dragon take care of her eggs. He also pit himself against a larger, stronger Titan Nightmare which was attacking them in order to dominate over it and protect the eggs.

The Titan Wing Monstrous Nightmare has shown to be fiercer and much more aggressive compared to average Monstrous Nightmares. They will fight for dominance over a female Monstrous Nightmare to have their own family, such as male lions do with a pride. Possibility that the Titan Nightmare may have killed the mate of the female Monstrous Nightmare. They will even destroy her first eggs to have their own eggs with the female.

Monstrous Nightmare can also store and heat fish by sticking them to its spines. The Nightmare can then engulf itself in flames and cook the fish, sort of like a barbecue.

If Monstrous Nightmares get a toothache, they would act strange, for example they won't eat for a few days. The dragon would then become agitated, act aggressive and then they will fire uncontrollably. As shown by Hookfang, tamed Monstrous Nightmares can also reject their owners and companions, usually only for a short while.

As seen in the comic, "Dragon Down", Monstrous Nightmares shed their scales periodically. This is a bit of a hazard for the environment and creatures around them, as the scales flame up and can start fires on the ground.

Training
The best way to earn the trust of a Monstrous Nightmare is simply to show it the respect it deserves. Placing a gentle hand on its snout and showing you are not a threat to it is the best way to go. Hiccup even shown to Hookfang that he was no threat to him as he toss his helmet and dagger away. While Nightmares are generally tough, tenacious and rebellious, mutual respect and trust will certainly help both parties in the long run.

As demonstrated by Snotlout and Astrid, pinning a Nightmare's horns to the ground can help calm them down. Violence like grabbing any of their body parts prove to be ineffective.

Like another dragons, feeding is bonding time that was stated by Snotlout as it might be hard for inexperience youngsters like Gustav who tried to feed Hookfang and Fanghook as both weren't able to get the fish correctly as it will be result for attack as proven by Fanghook.

Helping Monstrous Nightmare with a toothache problem will show their softer side as they grow aggressively as Gobber helped Hookfang and Hiccup helped Whip-Slash who had a hook.

A Nightmare has incredible stubbornness, making them hard to control and very disobedient, as well as the fact that they are very easily distracted by butterflies and flowers.

How To Train Your Dragon
In the beginning of the film, Hiccup narrates about the Nightmare just when a Nightmare comes snapping up a watch tower, coated with flames, but was promptly defeated by Stoick.

After Hiccup shot Toothless down, he excalimed happily, asking if anyone saw his achievement. A Nightmare emerged from behind him, causing a groan from hiccup. The next shot depicts Hiccup running away from the Nightmare. Stoick arrives at the scene just before the Nightmare corners Hiccup behind a brazer. The Nightmare runs out of shots and Stoick fights it fist-to-talon, finally, it flies away in defeat.

A Nightmare was kept prisoner at dragon training and the top of the class would've had the 'honor' of killing him. Hiccup was given the chance and instead, tries to connect to him and show the Vikings that dragons are not monsters, but after an outburst from Stoick, he becomes startled and begins to attack Hiccup in defense, until Toothless comes and protects his friend from the much bigger dragon, having no difficulty in subduing the enemy.

Later, when Hiccup is trying to get his friends to connect with the dragons and help fight the Red Death, the Nightmare is the first one he brings out. Snotlout Jorgenson is terrified enough to prepare a broken end of a spear as a weapon, in case Hookfang starts attacking, but Astrid nudges him to put it down. When Hiccup brings him closer to the others, he grabs Snotlout's arm so he can touch the dragon. Snotlout, obviously still frightened tries to resist, until Hiccup calms him and places his hand on his snout and he begins to growl in a purring manner. Snotlout's fear turns to amazement as he has made a connection. During the final battle of the Red Death, Snotlout is seen riding the Nightmare. After the events of this film, the Nightmare was named Hookfang they joined the rest of the team and appeared in almost every other episode of the series.

How to Train Your Dragon Live Spectacular
The Monstrous Nightmare appears in this theater production as a dragon opponent Hiccup must face to "win" the dragon games. As with the first movie, as Hiccup tries to befriend the dragon in a non-violent manner, Stoick steps in and angers it. Toothless comes to Hiccup's rescue and defeats the angry Nightmare.

Later on at the end of the production and the Vikings and dragons have united, Fishlegs is seen cooking large pancakes with a Nightmare's fire.

Book of Dragons
Bork and his Wife sat by a campfire and fried corn on it when the scent attracted a Monstrous Nightmare. The dragon appeared before them, and he attacked the ferocious Nightmare with the frying pan spilling the food in the process. The Monstrous Nightmare disarmed Bork, ate the food and retreated. Bork took two pieces of corn and tried to use it as a weapon against the dragon, but failed when the dragon burned Bork by lighting himself on fire (creating popcorn in the process). Hiccup said to befriend a Monstrous Nightmare by giving it respect and a gentle hand its snout.

Dragons: Riders of Berk
Monstrous Nightmares are shown to inhabit Outcast Island in "Alvin and the Outcasts". Nightmares and other dragon species routinely attack the Outcast Tribe.

In "Heather Report, Part 1", the Outcasts were trying to train it, but with no results. In Part 2, he was the dragon chosen for Astrid, who was hoping for a Deadly Nadder, to train. She first tried to approach him slowly, but he flamed up, knocking her back. Astrid then tried the direct approach by grabbing his tail. This just made the dragon angry and flung her off. Astrid then remembered how Snotlout pinned Hookfang's horns to the ground to calm him down, and did the same to the fiery reptile. He was relaxed and bonded with Astrid. When Alvin brought out Heather's adoptive parents, she punched the Monstrous Nightmare's nose, after apologizing, so he would flame up and attack. He returned at the end when Alvin was about to throw Astrid off a cliff and saved her. It is assumed he is now living on Berk.

Dragons: Defenders of Berk
Fanghook, a pink Nightmare, first appeared in "The Flight Stuff" when Gustav Larson was looking for his own dragon. After rejecting the Terrible Terror and the Deadly Nadder, he found Fanghook chasing boars, picking him because Snotlout described the Monstrous Nightmare as "the most lethal dragon in the known world." However, due to Snotlout's "training," Gustav's relationship with Fanghook was like Snotlout and Hookfang's. Gustav decides to head to Outcast Island after overhearing about the scouting mission from Trader Johan. The two easily get captured in Dagur's new trap, but are soon released by Hiccup. They then work with Snotlout and Hookfang to save Hiccup and Toothless. The next day, Gustav releases Fanghook back into the forest. After Hiccup and Snotlout leave, Gustav calls his dragon and the two continue training together in secret. The duo appeared in several other episodes and are the leader of the Auxiliary Team.

Season 1
In "Total Nightmare", Snotout believes that Hookfang is going feral after he repeatedly breaks out of his stable to meet a female Nightmare. In an attempt to convince him to return, Hookfang out rightly chose the female's side. Dismayed, Snotlout announces that he does not want to be a rider anymore. The gang quickly round up more Nightmares, but Snotlout refuses, naming them Hookfire, Fangmaster and Hookblazefang as they remind him of Hookfang. They were quickly sent away. As Snotlout leaves, he sees Hookfang laying on the ground. Thinking that the female abused him, Snotlout charges forward, ready to attack. However, the arrival of a Titan Nightmare draws all their attention. The dragons charge, but the Titan sweeps them all off their feet. Snotlout realises that the female had called Hookfang for help in protecting her young from the Titan and recounted everything to the gang when they arrive. Snotlout mounts Hookfang and lures the Titan away from the eggs with a series of winding routes, using its lack of agility against it. They quickly head to the Edge and trap themselves in the dome. They corner the Titan inside and fire at it. Finally, the Titan concedes defeat and leaves.

Season 2
In "Team Astrid", Astrid helped Sven train his Nightmare. The duo then joined the Auxiliary Riders and helped defend the Edge in that episode. They also attempted to defeat the Frozen Skrill in "A Time to Skrill", but failed.

In "Night of the Hunters, Part 1", a captive Nightmare was seen inside a dragon-proof cage. While a Dragon Hunter taunted him from outside, Ryker Grimborn warned him not to as they were smarter than him. Cagecruncher lurched forward, nearly hurting the hunter. Ryker had backed off just in the nick of time, claiming that dragons weren't smarter than him.

Firescrapes can first be seen together with Scardian and the rest of the pack when they faced off Trader Johann and kidnapped Fishlegs in "Edge of Disaster, Part 1" and "Edge of Disaster, Part 2". He is later seen several times standing beside Scardian, and later patrolling at night. He was later tamed by Hiccup and aided them at Dragon's Edge to fight off Dagur.

Season 3
In "Follow the Leader", Tuffnut and Ruffnut attempted to get kerosene gel from a wild Nightmare. The dragon, however, attacked them and the twins were unsuccessful.

In "Stryke Out", a fighter Nightmare known as Whip-Slash is introduced. Whip-Slash was first seen fighting with Steeltrap when Ryker visited the Fight Master. When Hiccup got captured, Whip-Slash threatened him. Later, Hiccup gave him a fish but the dragon spit it out. Then, Hiccup pulled a hook out from his mouth and gave him the fish again. This time, the dragon ate the fish. Later, Whip-Slash and Steeltrap tried to melt the menacle tight from a Fighter Razorwhip's tail but failed. Whip-Slash was freed when the Dragon Riders came and drstroyed the arena.

Season 5
In "A Matter of Perspective", the Dragon Riders travel to Vanaheim, the final resting place of the dragons. There, they find tombs of different dragon species, including one of the Monstrous Nightmare.

Season 6
While they were searching for willow trees in "No Bark, All Bite", Hiccup and Stoick ran into a flock of fleeing dragons. Stoick then ordered Skullcrusher to smash into a Monstrous Nightmare that immediately light up. Toothless then shoot a blast at the dragon, scaring it away.

Many Monstrous Nightmares were summoned by the Berserker Bewilderbeast during the final battle in "King of Dragons, Part 2". They helped in fighting the Dragon Hunters and Dragon Flyers.

How to Train Your Dragon 2
During Valka's recount of her experience just before leaving Berk to Hiccup, a Nightmare appeared in her flashback during a dragon raid. It was shot down and a Viking approached it, ready to end its life. Valka stepped forward and stopped him. The Viking reluctantly left for other dragons and when the Nightmare was said, it was said to join Valka.

How to Train Your Dragon: The Hidden World
When the people of Berk decided to move to the Hidden World, all the Monstrous Nightmares of the island began the journey too, carrying different things, such as ships. They eventually arrived at New Berk, where they settled down for a while.

Many wild Monstrous Nightmares were among the myriad of dragons in the Hidden World who bowed down in front of Toothless and the Unnamed Light Fury, showing respect for their Alpha.

After Grimmel the Grisly captured Toothless, all the Monstrous Nightmares from Berk, along with the other dragons, came to their Alpha's help. However, Toothless ordered them to stop when Grimmel threatened to kill the Light Fury.

Fortunately, the Dragon Riders began an attack on Grimmel's ships and freed the Monstrous Nightmares, along with the other dragons, which returned to New Berk.

When the battle ended, Hiccup realized that the only way the dragons can be safe from humans was for them to go to the Hidden World. After Toothless gave the command to the dragons of Berk, all of them, including the Monstrous Nightmares, said their farewells to the Vikings and flew off to the Hidden World.

The Stowaway
When Hroar goes to Dragon Island in order to enrage many dragons and lead them to Berk, he does so with several Monstrous Nightmares. However, after he is thrown off his saddle, the Monstrous Nightmares and all the other dragons return to their island.

DreamWorks Dragons: Wild Skies
This dragon is available on Lava-Lout Island in Wild Skies. Described as 'Stop Drop and Roll, Explosive Nightmare', training the Nightmare will unlocked the 'Stop Drop and Roll' achievement.

Dragons: Rise of Berk
The Nightmare is the first searchable dragon in the game. Plenty of individuals like Hookfang, his mate and offsprings, Fanghook, Fangmaster, Sven's Nightmare, Girl Hookfang, Firescrapes, Cagecruncher, Exiled Monstrous Nightmare, Valka's Mercy, Whip-Slash and Liberated Whip-Wreck are available in the game.

School of Dragons
The Monstrous Nightmare is one of the original dragon species available for riding in this game. A Titan form as released later.

A fossilized skeleton of a Monstrous Nightmare can be seen on Auction Island, put on display by the seedy vendors there.

Dragons: Titan Uprising
Several Monstrous Nightmare individuals, like Merciful Nightmare, Blazing Phoenixfire, Mountain Nightmare, and Charsoul, and hybrids, like the Abomibumble, appear in this game.

Dragon Pets
A Monstrous Nightmare is one of the three dragons that appear in this game, along with the Deadly Nadder and a Gronckle.

Trivia

 * The Monstrous Nightmare shares some resemblances with the dragon Smaug from The Hobbit franchise.
 * Some Monstrous Nightmares are shown to have tines on their horns like deer. The number of tines could indicate the age of the dragon. For some reasons, Hookfang does not have any tines on his horns, but this actually helps Snotlout to tell him apart from other Nightmares. Aside from getting tines for age, Nightmares also get barbells on their chin.
 * In the concept art, it is shown that Monstrous Nightmares have barbells at least three through five but a bit longer then the counterparts from the franchise. So older Monstrous Nightmares barbells might grow longer when aging.
 * Monstrous Nightmares have a tendency to spit fire at times, unintentionally, like coughing, sneezing or laughing although most species shoot fire, or their ranged weaponry when coughing, or sneezing.
 * In Dragons: Rise of Berk, Monstrous Nightmares have three finger claws instead of two when turned into a Titan.
 * Dragons: Race to the Edge shows Titan Wing Monstrous Nightmares to be bigger and a darker color but without an extra claw finger.
 * They are shown to have prehensile tongues as one was able to grab its food. That could make sense as Hookfang often has his tongue sticking out.
 * Monstrous Nightmares seem to be much longer than their wings are wide.
 * Monstrous Nightmare is the third species to be seen in their Titan Wing form outside of the Dragons: Rise of Berk game. The first being the Gronckle in the Book of Dragons short, and the second is the Screaming Death.
 * Monstrous Nightmares and Cavern Crashers have bit in common as they both use a type of flammable gel or slime.
 * It is possible that the Monstrous Nightmare may be able to resist the Death Song's attack if it performs a fire burst. This way the amber substance might break upon contact with the Monstrous Nightmare's body.
 * As seen in "A Matter of Perspective", a Monstrous Nightmare's fire burst is due to his bones also being on fire.