13 books in series

How to Train Your Dragon

How to Train Your Dragon is a 16-book series with 13 released primary works first released in 1999 with contributions by Cressida Cowell.

Hiccup: The Viking Who Was Seasick
How to Train Your Dragon
How to Train Your Viking
How to Be a Pirate
How to Speak Dragonese
How to Cheat a Dragon's Curse
How to Twist a Dragon's Tale
A Hero's Guide to Deadly Dragons
The Complete Book of Dragons: A Guide to Dragon Species
How to Ride a Dragon's Storm
How to Break a Dragon's Heart
How to Steal a Dragon's Sword
How to Seize a Dragon's Jewel
How to Betray a Dragon's Hero
How to Fight a Dragon’s Fury
The Day of the Dreader