Hookfang is a Monstrous Nightmare, and is the size of a leopard in the books. In the movie he's huge, 60 feet long with a 65 foot wingspan. In the books, Hookfang actually belongs to Stoick and not Snotlout. According to Snotlout, Hookfang weighs around 5,000 pounds, and he can light himself on fire using his sweat. Hookfang is a perfect example of a typical Monstrous Nightmare. He has large shiny greyish-black horns that curve slightly outwards on the edge. He has bright reddish-orange scales with darker spots scattered around. His underside is a light tan, and he has yellowish orange eyes like most other dragons. Hookfang is the most commonly seen Nightmare, so most stock images are of him. His color scheme is fairly common in the movie, and Snotlout has even mistaken other Nightmares for him. Hookfang's horns lack extra antlers coming off of them, which does help to distinguish him from other Monstrous Nightmares seen in the film. He seems to be fully grown, and no Nightmares have yet been seen that are notably larger than him.
In the Books
In How to Train Your Dragon, he mocked Hiccup's new dragon Toothless for his small size when he first saw him. He is not mentioned in any other book except the first one. In the books, Hookfang is one of Stoick's dragons, along with Newtsbreath.
In the film
In the film, like the other main characters' dragons, he 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, Hookfang is the first one he brings out. Everyone is astounded by this, except for Astrid. Ironically, Snotlout 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 Hookfang 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, until Hiccup starts walking away to grab rope to "hang on" to the dragons, as the camera moves to reveal that the Gronkle, Deadly Nadder, and Zippleback are out of the cages, ready to be tamed.
During the final battle of the Red Death, Snotlout is seen riding Hookfang. When it is seen that Hiccup and Toothless have defeated the Red Death but Hiccup is no where to be found, everyone is upset. Toothless reveals that Hiccup is alive and everyone is overjoyed. Hookfang makes a brief appearance as he bows his head between two Vikings and is seen to make a "woo" sound with is eyes closed. The Vikings stare at the dragon in amazement.
At then end, Snotlout and Hookfang join the other dragons and trainers as they ride into the sky.
In Legend of the Boneknapper Dragon
In this short film, Hookfang makes a very short appearance. He's seen along with Snotlout, pouring water on Gobber's house, in an effort to put out the fire. Hookfang never appeared in this short movie after the above scene.
In Gift of the Night Fury
In the short film Gift of the Night Fury, he becomes a father. He's even the one to fly Hiccup back home with the other dragons and their hatchlings. When they get home and land, Snotlout runs over and hugs his snout, as they are both ecstatic to see each other. At the Snoggletog party, Snotlout is seen playing with one of his children.
In Riders of Berk
In Riders of Berk, Hookfang is shown to disobey and neglect Snotlout (the only Viking from the main cast that can't control his dragon).
In Viking for Hire, Hookfang behaved aggressively and Gobber was going to kill him. But after seeing that he only had a toothache, Gobber quickly fixed this by pulling it out.
In In Dragons We Trust, Hookfang runs off to chase a bird as soon as he was put on Dragon Island, unlike the other dragons.
Snotlout and Hookfang have a unique relationship. It is shown that Hookfang does hold some affection for his owner, but Snotlout's immaturity and idiocy leaves him holding disrespect (mimicking Snotlout's "respect" for him). It is often implied throughout both series that Hookfang's disobedience and willingness to undermine Snotlout may partly be to keep his rider's overabundent ego and self-righteousness in check, as he often acts out when Snotlout attempts to assert his superiority over him or the others
He also seems to take callous pleasure in making Snotlout scream when they are out for a flying ride. He disobeys Snotlout most of the time, but in Defiant One, Snotlout says to go North when Hiccup says to go South. Wanting to keep on go with the others, Hookfang doesn't respond until Snotlout looks his dragon in the eye and says, "Hey, you work for ME!" Later in the episode, Hookfang is seen carrying Gobber as an attempt to save Snotlout, Hiccup, and Toothless from Outcast Island. Hookfang also gets distracted easily, like chasing a seagull or watching a leaf fall. He may have learned this behavior from Snotlout, as well as his rebellious, deliberately disobedient attitude towards his rider, which mirrors Snotlout's attitude towards Hiccup in the academy.
Defenders of Berk
In Race to Fireworm Island, Hookfang's flame goes out, putting his life at risk. In this episode it's shown that Hookfang did really care for Snotlout, proving this when he throws the Fireworm gel instead of consuming it, to save Snotlout from getting killed by the Fireworm Queen. In Fright of Passage, Hookfang showed a definite amount of impertinence towards Snotlout, as evidenced by the look he gave Snotlout as he entered Ruffnut and Tuffnut's secret hideaway.
Abilities and Skills
From hard training from Snotlout, some of Hookfang's abilities and gain skills are better than those of a regular Monstrous Nightmare
Strength: Hookfang is shown to be a very powerful dragon that he can lift heavy objects and people, he can easily lift up Alivin and his rider at the same time while on his neck to fly in the air. Hookfang tail whip can send his rider far distance. His wing strength shows that can he stop a speeding 5,724lbs Meatlug with extra weight of her rider on her back.
Fire: Hookfang can shoot a powerful stream of flaming viscous gel like a flamethrower, he can also set himself on fire by sweating the gel or coating himself with his saliva. In Cast Out Part II, Hookfang was seen to capable of creating more powerful fire shot by circling in the air to form a concentrated fire ball in the center of the circle. His fire jacket have shown to be lighting up any part of bod.
Swimmer: Hookfang can swim under water very well with high speed and looks like he can hold his breath for a while or longer without his rider. His body have shown to be on top of the water being like alligator.
Speed: Hookfang is very fast at flying, being able to keep up with Toothless at the Thawfest games but ultimately not as fast as Toothless though. This may be the result of his hard training with Snotlout. Snoulout had stated that Hookfang speed isn't fast as Stormfly. He is also relatively fast when running on the ground.
Acrobatics: He is shown to be very well with his flexible body like his tail and neck. As for agility, he's shown to be well to crawl down on chain, his reflex is great to react fast enough from attacks, and his balance is good for standing up straight also good for counter balance in the air at flying to make quick turns but not as fast like Toothless.
Agile: Can dodge attacks very well compare to other dragons but not as well as Toothless. He is shown to be agile enough to dodge Skrill blast but for his rider was shocked many times.
Jaw Strength: Can fit his rider's torso in his mouth but does not bite at full force. Also can pick up a boulder with his mouth with no trouble whatsoever.
Endurance and Stamina : Shown to be very well to be able to take hits contiune to fly and keep flying at full speed with hard training even being very exhausted. Even when he was sick he can still fly high and catch up to the other dragons showing his stamina. But when he getting more sick he was flying lower still able to keeping trying to stay with the group.
Intelligence: He shown to be very intelligent by understanding what his rider orders him to do. But sometimes he dislikes some of his orders from Snoutlout usually gets back at him by attacking or leaving him somewhere to show he is smarter than his rider. Another way proving he is very intelligent is getting into a exclusive safe house of Ruffnut and Tuftnut hide out.
- Hand Signals He learn it easily "annihilate" for breathing his fire but for his other command "stealth" was tricky showing to stepping to hard to the ground.
Wing Blast: Hookfang is able to push objects away from him with a flap of his large powerful wings for far distance. He shows that he can blow away Barf's entire gas. Hookfang can also use his wings to force his fire into a devastating attack.
Loyalty: Hookfang is loyal to his rider saving him few times from death but sometimes showing to be lack of loyalty by mistakes and teaching Snoutlout lesson. He does shown to be very loyal when Snoulout is very close to certain death like the the Fireworm Queen or Screaming Death.
Synchronization: Hookfang has shown to be good as Snoulout like's to be reckless. The other way, like most dragons, they do is they both show to be very tough and mean like Snoulout is mean to the other Viking teens and Hookfang can be mean to the other dragons.
Fighting Style: He shows mostly shows his roar and size against his enemy's to be fear and using his fire jacket as well. In fighting mostly shows his fire power against his enemy's. If fight against another dragons using his wings to fight back and wings to use as shield for attacks from other dragons.
Rescue Skills: Hookfang was train to save alone Viking on a boat and also he was train by Snoulout take out fire on person by stopping them.
Wall Climbing: Hookfang can climb to the mountain by walking on woth his claws and talons
Like his rider, he is somewhat of a bully and aggressive. However, he is much nicer to others but likes to torment his rider possibility to show his rider he is a tough dragon. But in reality, he cares about his rider well-being very deeply. He shown to have great relationship to his rider.
- Hookfang has a habit of letting his tongue dangle from his mouth.
- While disobedient to Snotlout, Hookfang is more gentle to the other Vikings like Hiccup, Heather, and Stoick. He will even listen to Fishlegs' commands.
- Like Snotlout and Hiccup, Hookfang has a rivalry with Toothless (though it is more downplayed and implied).
- In How to train your dragon 2, Hookfang does not have tines on his horns which indicates that he is still young or the tines have really gone because he's really an old Nightmare (or the tines could be a production goof or he might simply not have any and its really just a random trait for his species).
- He may also have adopted Snotlout's dislike of authority.