A Hero's Guide to Deadly Dragons is the sixth book in the How To Train Your Dragon book series, published on November 1st 2008.
The book begins with Hiccup on the ledge of the only window to the Meathead Public Library which, is not open to the Public on the stroke of 12PM on his 12th birthday. Books are in fact considered dangerous and should be locked up. They were all locked up and guarded by 400 Meathead soldiers, their Driller-Dragons and the Hairy Scary Librarian. He was about to slip in thinking to himself,
- "What AM I doing? This is my BIRTHDAY, for Thor's sake. I should be sitting at home enjoying myself instead of risking my neck three hundred feet in a Library of Doom. . . . What AM I DOING? HOW DID I GET MYSELF INTO THIS MESS IN THE FIRST PLACE? NOTHING could possibly be worse than this. . . ."
He then loses his footing and ends up hanging by one hand on the ledge with 400 arrows pointed at him, and driller dragons flying at him.
Then, it goes to the next chapter to show how he got into that tricky situation. He woke up at 7 AM and made a wish that it would be a peaceful day. He then tried to get Toothless to eat a healthy breakfast and for a dragon, that means eating spinach and wood. Toothless was then supposed to eat driftwood that Hiccup put on the plate. When Toothless wouldn't eat it, Hiccup left him there to eat the wood and spinach. He then went to the finals for a burglary competition, where the Hooligans were thoroughly beaten by the Bog-burglars in every event. He met up with his friends Fishlegs and Camicazi. She had managed to steal several things including Stoick's underwear.
When they walk into Hiccup's house, the room is covered in spinach and Stoick's new wooden throne is charred and has been mostly eaten. Toothless is found sitting in the middle of it looking guilty. Stoick then walks into the room and, already in a bad mood on account of the bet he made with Big-Boobied Bertha that the Hooligans were just as good at burglary than them, loses his temper when he sees his throne. Fishlegs almost calms him down when one of the legs on the chair fall over and Camicazi laughs. Stoick then notes that she has a pair of his underwear. Stoick then threatens to banish her if she does any thing like it again. After Stoick leaves, Hiccup sees that Toothless destroyed the book that his father had left to find, thinking it would win him the bet. They had gotten transportation to the library by a stealth dragon stolen by Bertha from Madguts the Murderous. Then, they go to the tower were all the books are kept and find driller dragons chasing after them. Then, they escape and run off into the library looking for the book, how to train your dragon, carefully navigated by stormfly, Camicazi's dragon. They find the book when the hairy scary librarian comes and sees them lurking in the library. They fight and Fishlegs get's a book that teaches you how to become a very good fighter and smacks it on his head. He falls and the Red Hot Itchywoms tickle him and he laughs after 20 years. They run off with the book. One the way back, Stormy gets knocked out and forgets the way around the library whilst the army of 1000 of warriors, protected of the castle try and capture then, with the help of their dragons.
They run away and find the Driller Dragons chasing after them. They run and Hiccup finds his ancestor's book (Hiccup Horrendous Haddock II) which was called A Hero's Guide To Deadly Dragons and picks it up and sees a hidden entrance to get away as there was no other exit. They see Poisonous Piffleworms which can kill you with one drop of their poision, instantly. They make them not get up by making loud noises, which makes them stand still. They throw one of the Poisonous Piffleworms at the Driller Dragons who run off. Hiccup and his friends run off with the stealth dragon. Meanwhile, the hairy scary librarian tries to kill Stoick The Vast. HIccup comes with the stealth dragon and drop on top of the hairy scary librarian. Then, Madguts the Murderous comes and is about to kill Big Boobied Bertha when Hiccup says that the hairy scary librarian was the one who stole his stealth dragon and as a result of this, he gives her his favourite sword. He takes the librarian away in a jail cell when he wakes up, after being knocked out.
In the end, Hiccup asks for his birthday, that all the books should be allowed to be read by the vikings. He agrees and Stoick wins the 2 axes as Hiccup gave him the book and Big Bobbied Bertha's stealth dragon was taken away by Madguts The Murderous.
- Hiccup Horrendous Haddock III
- Stoick the Vast
- Big-Boobied Bertha
- Hairy Scary Librarian
- Madguts the Murderous
- Madguts's Stealth Dragon
- Madgut's Sniffer Dragons
- Red-Hot Itchyworms
- Poisonous Piffleworms
- Seadragonus Giganticus Maximus
- Stealth Dragon
- Sniffer Dragon
- Red-Hot Itchyworm
- Poisonous Piffleworm
- This is the only book not to start with "How to..."
- The epilogue contains not only the typical epilogue, but also a few dragon profiles and a Dragonese dictionary, complete with scenarios featuring Toothless and Hiccup.