How To Train Your Dragon #6: A Hero's Guide to Deadly Dragons by Cressida Cowell
It’s Hiccup’s birthday, but that’s not going to keep him from getting into trouble. To save his dragon, Toothless, from being banished, Hiccup must sneak into the Meathead Public Library and steal the Viking’s most sacred book. But the Vikings see books as a dangerous influence, and keep them locked up and under heavy guard. To save his friend, Hiccup must brave the Hairy Scary Librarian and his dreadful army of Meathead Warriors and face off against the formidable Driller-Dragons. Will he make it out and live to see his next birthday?