At the introduction of the Wodensfang, Hiccup assumes he is a small species of dragon. However, he later learns that Wodensfang is actually an elderly Seadragonus Giganticus Maximus.
When the Seadragon Merciless was fighting to eradicate humankind, he sent the Wodensfang to kill Hiccup Horrendous Haddock I, as a prophecy foretold that Merciless would be killed by a Hiccup. Wodensfang was caught in some branches when he was searching for Hiccup I and left to die, but Hiccup I nursed him back to life. In return, Wodensfang taught Hiccup Dragonese and Hiccup taught him Norse. Wodensfang told Hiccup I where to find the Dragon Jewel and made him swear not to use it for evil. Hiccup I used the Jewel to teach dragon to fish, hunt and other stuff. Hiccup I then used the Jewel to banish Merciless from the Archipelago.
After Hiccup I's death, humans started using the Jewel for their own purposes. Wodensfang confronted the last King of the Wilderwest, Speedfast, later known as Grimbeard the Ghastly, about how was mistreating both humans and dragons. Speedfast banned Dragonese and made the Dragonmark, which was meant to be the mark of the king, into the Slavemark, believing he would be a greater leader than his ancestors. Many years later, after seeing his mistakes, Grimbeard told Wodensfang to guard the Crown and kill anyone who tried to use that power again.
Hiccup meets Wodensfang while trying to retrieve the Crown. At first meeting, Hiccup "didn't recognize the species" (pg. 198) and the little old dragon introduces himself:
- "Well, Hiccup the Third, I am the Wodensfang."
- ―pg. 200
Hence forth Hiccup refers to him as the Wodensfang, as though this is a species name. In actuality, he is a Seadragonus Giganticus Maximus, but with age has shrunk in size to that of a lap-dragon, not much larger than Toothless. He is well over 1,000 years old.
Wodensfang tells Hiccup about his ancestor. When Hiccup promises to use the Throne of the Wilderwest to free all dragons, Wodensfang agrees to let Hiccup take the crown and live. When Furious and the Red-Rage Dragon Rebellion attack, Wodensfang, the Windwalker and Toothless flee with Hiccup.
A year after the events in the previous book, Wodensfang continues to help Hiccup find the Dragon Jewel. He constantly reminds Hiccup about Furious sending a dragon to eliminate him as well. He and Toothless are captured by Alvin, and Excellinor forces Hiccup to find the jewel. After he does, Hiccup frees Toothless and Wodensfang, but loses the jewel.
Hiccup confines to Wodensfang later about how Furious told him he would bring the end to the dragons, since Alvin only has the Lost Things because Hiccup found them. Wodensfang tells him not to worry, and to have faith for the future. He has doubts himself, but Wodensfang convinces himself that humans and dragons CAN live together.
Wodensfang is revealed to be Seadragonus Giganticus Maximus, as well as able to speak Norse. Later that night, Toothless dreams of the conversation Wodensfang has with Furious, which is actually happening! Wodensfang agrees he will betray whoever becomes King of the Wilderwest if Furious agrees to stop tracking them through his and Toothless' thoughts. Their conversation also reveals that Toothless is a Seadragonus Giganticus Maximus as well, much to his displeasure. Wodensfang then erases Toothless's memory, so all he knows is that he had a bad dream, but can't remember what it was about.
At the end of the book, the Wodensfang is with an unconscious Hiccup, desperately hoping he'll wake up.
When Hiccup does wake up, he has amnesia, and has forgotten his name and his quest, and even his favorite color, but not the air speed velocity of an unladen Windwalker. Wodensfang attempts to explain to Hiccup the momentous events that are unfolding, but is rendered unconscious by a Sandshark's dart. Wodensfang only recovers after Hiccup has been crowned King, and is surprised that Hiccup hasn't found the "true" dragon jewel. His plan had been to take the fake Jewel to the Dragon Furious leaving the True Jewel with Hiccup. He flies with Hiccup to single combat and attempts to help Hiccup make peace with the rebel dragons.
- While Toothless did not like the Wodensfang at first, the two eventually become friends.
- The Wodensfang's agreement to betray the new King of the Wilderwest may not be completely directed at Hiccup. He never actually says he'll betray Hiccup, just the King.
- This ultimately turns out to have been a red-herring, and Wodensfang promise to betray the king was intended to have been a double-cross, regarding the true nature of the Dragon Jewel.
- Wodensfang is shown to genuinely care about Hiccup and Toothless, as he truly believes the boy can somehow stop the rebellion, as well as erases Toothless memories so he won't worry.