Chronicles the adventures and misadventures of Hiccup Horrendous Haddock the Third as he tries to pass the important initiation test of his Viking clan, the Tribe of the Hairy Hooligans, by catching and training a dragon.

Someone has stolen the Fire Egg. Now the Volcano on Volcano Island is active and the tremors are hatching the eggs of the Exterminator dragons! Can Hiccup return the Fire Egg to the Volcano, stop the Volcano from erupting, and save the Tribes from being wiped out by the terrible sword-claws of the Exterminators.

Hiccup, stranded with Toothless on the Beach of the Broken Heart and being hunted by an old enemy, faces Ug the Uglithug, Berserks, and Scarers and tries to save Fishlegs from the Beast.

Now chief and ruler of Berk alongside Astrid, Hiccup has created a gloriously chaotic dragon utopia. When the sudden appearance of female Light Fury coincides with the darkest threat their village has ever faced, Hiccup and Toothless 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, dragon and rider will fight together-to the very ends of the Earth-to protect everything...

When it becomes clear that the new generation of Vikings doesn't remember the bond between dragon and human. Hiccup sets a plan to celebrate dragons with a grand Snoggletog holiday pageant and gets a heartwarming surprise visit from Toothless for one more adventure.