The "How to Train Your Dragon" book series by Cressida Cowell consists of 12 main novels published between 2003 and 2015, following the adventures of a young Viking named Hiccup Horrendous Haddock the Third. The titles in the main series are:

1. How to Train Your Dragon (2003)
2. How to Be a Pirate (2004)
3. How to Speak Dragonese (2005)
4. How to Cheat a Dragon’s Curse (2006)
5. How to Twist a Dragon’s Tale (2007)
6. A Hero’s Guide to Deadly Dragons (2007)
7. How to Ride a Dragon’s Storm (2008)
8. How to Break a Dragon’s Heart (2009)
9. How to Steal a Dragon’s Sword (2011)
10. How to Seize a Dragon’s Jewel (2012)
11. How to Betray a Dragon’s Hero (2013)
12. How to Fight a Dragon’s Fury (2015)

There are also supplementary books and related titles, including illustrated guides and short stories, such as "How to Train Your Viking" and "The Day of the Dreader".