The books are set in a fictional Fantasy Viking world, and focus on the experiences of protagonist Hiccup Horrendous Haddock the Third, as he overcomes obstacles on his journey of "becoming a hero, the hard way".

Cowell has published twelve full novels, based around the adventures of a young Viking named Hiccup Horrendous Haddock the Third.

[8][9] The first book in the series follows Hiccup as he captures a dragon as a rite of passage and attempts to train him so that he will not be exiled from Berk, as is its tradition for young Viking boys on this island.

As this is seen as failure to train the dragons correctly, all the boys are sentenced to exile, but allowed to stay one night while a storm rages.

Hiccup then escapes with the help of Toothless, who chose to act selflessly, killing the Green Death in the process.

As the party begins to explore the cavern they come to a door and upon opening it, they find the real treasure of Grimbeard the Ghastly.

The creature's nervous system is destroyed and they escape, but Hiccup decides that the world is not ready for the treasure, and leaves it behind.

Hiccup causes a distraction and escapes with Fishlegs, but not before a Roman prefect grabs and tears away half of his How to Speak Dragonese notebook.

Alvin manages to get his hand-hook lodged into the balloon basket, but the children are able to twist him off, and he falls into Sharkworm-infested waters.

Old Wrinkly predicts the potato might be in the Hysteric Territories, and tells him that he must bring it back before ten o'clock the next morning, or else Fishlegs will die.

The two children enter through the roof, but Hiccup falls into a pot of onion soup, and is discovered by Norbert the Nutjob.

After the Hysterics fall asleep, Camicazi picks the lock of Hiccup's cage and they leave the Hall through the chimney.

Hotshot begins to tell Hiccup his story of how he fell in love with a Viking woman, but her father wanted her to marry someone clever.

Madguts puts Stoick and Bertha in jail and promises he will execute them as his reward for winning the race in three months.

Because Hiccup is the last person back, he demands Madguts sing a love song at the next "Thing" while dressed up as an "ickle pretty shepherdess".

Hiccup now realises that he wants to be a great King who abolishes slavery and who founds a New Word in the Old World, not far across the ocean.

Grimbeard’s wife, Chinhilda, leaves him and sails to the Uglithugs island searching for her lost son, where she eventually became the legend of the crying woman.

The other two sons sire their own generations, with the one who betrayed Hiccup, Thugheart, banished and forming the Outcast tribe and the other, Chucklehead becoming chief of the Hooligans.

Hiccup finds the crown under Flashburn's school, guarded by an ancient small brown dragon called the Wodensfang.

The book starts with Hiccup in exile on the run with the Wodensfang, Windwalker and Toothless, deactivating dragon traps and freeing slaves.

He is nearly killed by his mother, Vallhallarama, who doesn’t recognize him with his helmet and accidentally drops a tree trunk on her head.

Hiccup meets a little girl named Eggingard who is the sister of the Wanderer boy Bearcub from How to Ride a Dragons Storm.

She tells Hiccup how Fishlegs was dragged under the surrounding wet sand by the hand of a dragon with eyes on its fingers.

The Deadly Shadow gets caught in a trap and tells him that they had promised to care for Fishlegs when he was a baby when they were owned by his mother Termagant.

Hiccup persuades the rest of the group to save him, accidentally waking up Snotlout's Hogfly and the nearby Rebellion dragons.

Hiccup and Snotlout manage to escape into the open ocean with the boat with the ten lost things, but are being chased by Alvin and the witch on dragonback.

Once Hiccup reaches Tomorrow, he makes his way to Grimbeard the Ghastly's castle just as Alvin is about to be crowned king by the Druid Guardian.

The epilogue shows how Hiccup built a new kingdom of harmony on Tomorrow where humans and dragons could live in peace.

A live-action adaptation of the first animated film is set to release in 2025, starring Mason Thames as Hiccup and Butler reprising his role as Stoick.

All twelve novels have been recorded as audio-books and released by Hachette Audio, narrated by actor David Tennant,[10] who also plays the voice of Spitelout, Snotlout's father, in the film adaptations and in the series DreamWorks Dragons.