Hookfang is a Monstrous Nightmare, and is the size of a leopard in the books. In the movie he is huge, 50 feet long with a 60 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 saliva. 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 Book
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 and his 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 Nader, and Zippleback are out of the cages, ready to be tamed.
During the final battle of the Red Death, Snotlout is seen to ride the Monstrous Nightmare. 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 is 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, it is revealed that Hookfang is the name of Snotlout's Monstrous Nightmare. He becomes a father. He is 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 butterfly 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).
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 does not respond until Snotlout looks his dragon in the eye and says, "hey, you work for ME!" Later in the episode, Hookfang is seen to carry Gobber as an attempt to save Snotlout, Hiccup, and Toothless from being hostile on Outcast Island. Hookfang also gets distracted easily, like chasing a seagull or watching a leaf fall. He may have learned this behavior from Snotlout.
Defenders of Berk
In Race to Fireworm Island, Hookfang's flame goes out, putting his life at risk. In this episode it is shown that Hookfang did really care for Snotlout, proven 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.
Abilites, Weapons, 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; 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. His wing strength shows that can he stop speeding Meatlug with her riding 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.
Weapons: Hookfang's choice weapons are his horns, head, claws, talons, sharp teeth, tail, and his wings to either defenses or offense.
Swimmer: Hookfang can swim under water very well with great speed and possibly can hold his breath for a while or longer without his rider.
Speed: Hookfang is also 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 training with Snotlout. He is also relatively fast when on the ground.
Acrobatics: shown to be every well like flexible tail and neck, agility shown to be well to crawl down on chain, reflex is great to react fast for reacting attacks, and balance is good for standing up straight also good for counter balance in the air at flying to make turns.
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 his rider was shocked many times.
Jaw Strength: Can fit his rider's torso in his mouth but does not bite at full force.
Endurance: Shown to be very able to take hits and keep flying at full speed with hard training.
Intelligent: He shown to be intelligent by understanding what his rider orders him to do but he dislikes it so he usually gets back at him by attacking or leaving him somewhere to show he is smarter than his rider. He also proven to be little smarter then his rider getting into a exclusive safe house of Ruffnut and Tuftnut hide out.
Hand Singles: He learn it easily "inanimate" for breathing his fire but for his other command "stealth" was tricky showing to stepping to hard to the ground.
Wing Flap: Hookfang is able to push objects away from him with a flap of his large wings. He shows that he can blow away Barf's gas.
Flaming Wing Flap: Hookfang will spin around then breath fire and then clap his wings to releases the fire attack.
Loyalty: Hookfang is loyal to his rider saving him few times from death but sometimes showing to be lack loyalty by mistakes and teaching him lesson. He does shown to be very loyal when Snoulout is very close to certain death like the screaming death.
- '"Synchronization"': Hookfang have shown to be good as Snoulout like Being reckless.
- '"Flying Style"': Shown to be fly like average Monstrous Nightmare but seems to flying his own way by using full speed seem to be very joyful for Hookfang.
- '"Fighting Style"': He shows mostly shows his roar and size against his enemy's to be fear and using his fire jacket as well.
- 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).
- On How to train your dragon 2 book Hookfang is shown and he still does not have tines on his horns which indicates that he still young or the tines have realy 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).