Hookfang and Newtsbreath met Toothless after he woke up from Winter hibernation. Newtsbreath greeted Toothless, but Hookfang said that they must wait until they are alone to give Toothless a proper welcome. Hookfang then swiped at Toothless, which caused Toothless to howl in pain. Stoick then proceeded to yell loudly at both Hookfang and Newtsbreath, telling them to "GEDDOUTOFHEREBEFOREIMAKEYOUINTOHANDBAGS!". Hookfang and Newtsbreath then left the room muttering curses towards Toothless.
Hookfang is a Monstrous Nightmare. According to unofficial viking law, only a chief and the son of a chief can own one.
How to Train Your Dragon indicates that he is "about the size of a leopard" and has yellow eyes.
Hookfang appears to fear Stoick to some degree like all hunting dragons and their trainers, based on the fact that when Stoick yelled at him and Newtsbreath, telling them to get out or he will make them into handbags, Hookfang and Newtsbreath obeyed, but they were still shown to be annoyed and somewhat arrogant.
Hookfang and Newtbreath appear to be friends to some degree based on their interactions.
Hookfang enjoys bullying Toothless, just like Newtsbreath. This is shown when he lunges at Toothless, and scratches him slightly. Toothless ends up sleeping in bed with Hiccup every night instead of at the hearth, as there is a real concern that Newsbreath and Hookfang might eat him.
Hookfang is introduced in Book 1, when meeting Toothless for the first time.
|“||Newsbreath and Hookfang, Stoick's hunting dragons, came padding into the room. Toothless stiffened as they paced into the room. Toothless stiffened, their yellow eyes glinting evilly. Each was about the size of a leopard, and they were as delighted by his arrival as a couple of giant cats might be by that of a cute kitten||”|
|— Book 1|
- Later in the Book series, Monstrous Nightmares were said to join the Dragon Rebellion against humans. It is unknown if Hookfang did, as well.
- In the How to Train Your Dragon franchise, Hookfang is owned by Snotlout Jorgenson rather than Stoick.