Shy teen Hiccup must prove to his father and his village that he can still be a viking warrior — even if he'd rather befriend a dragon than slay one.
With Hiccup and Toothless on the verge of finally discovering their true purpose -- namely becoming Berk's village chief and a dragon leader of his own kind, they first must face the appearance of a female Night Fury, whose power will test the bonds of their relationship like never before.
Five years after the Vikings villagers of Berk and the dragons made peace, they live together in harmony. Hiccup and his dragon, Toothless, discover and map unexplored lands. Now 20 years old, he is being pressed by his father, Stoick the Vast, to succeed him as chieftain, although Hiccup feels unsure he is ready.
When it becomes clear that the new generation of Vikings doesn't remember the bond between dragons and vikings, Hiccup makes a plan to celebrate dragons with a grand holiday pageant. This heartwarming idea leads to a series of hilarious and exciting events, but no matter the circumstance, everyone in New Berk -- young and old alike -- is reminded that dragons and humans are forever bonded.
So you want to be a dragon trainer, do you? Prepare yourself for adventure, excitement and training as Hiccup, Astrid, Toothless and Gobber tell the legend behind the book of dragons and reveal secrets about new, never-before-seen dragons.
Right before Berk's traditional winter holiday of Snoggletog, all the dragons of Berk unexpectedly depart, leaving everyone distraught - except for Toothless, who cannot fly by himself. Out of compassion, Hiccup builds him a new automatic prosthesis allowing him independent flight, thus gifting him his freedom; he then flies off too.
Convinced that the legendary Boneknapper is responsible for burning his house down, Gobber enlists Hiccup and the Viking gang to hunt him down.
A hunt for a lost sheep turns into a competition between Hiccup and friends as they compete to become the first Dragon Racing champion of Berk.