Cressida Cowell

Now chief and ruler of Berk alongside Astrid, Hiccup has created a gloriously chaotic dragon utopia. When the sudden appearance of a female of Toothless' kind coincides with the darkest threat their village has ever faced, man and dragon must leave the only home they've known, and journey to a hidden world thought only to exist in myth. As their true destines are revealed, dragons and riders will fight together to protect everything they've grown...

Hiccup is a Viking teenager who aspires to hunt dragons, but doesn't exactly fit in with his tribe's longstanding tradition of heroic dragon slayers. His world gets turned upside down when he encounters a dragon that challenges him and his fellow Vikings to see the world from an entirely different point of view.