How to Train Your Dragon: Cressida Cowell draws Toothless and Hiccup
8 September 2015 Last updated at 16:17 BST
We caught up with How to Train Your Dragon author Cressida Cowell.
She showed Jenny how to draw the mischievous characters Toothless and Hiccup.
The twelfth and final book in the series is out today and is called "How to Fight A Dragon's Fury".