On a remote Viking island where dragons attack regularly, starts the story of a boy “Hiccup”. He is the son of the Chief Stoic the Vast, however, he is small in nature and is deemed not fit with the Vikings. That is why he spends most of his time helping Gobber, the town’s blacksmith. As he is an inventor, he invents this new device to shoot dragons. And just like many of his other inventions, it does not really work well, except he succeeds at shooting down an extremely dangerous race of dragons.
When no one believes he was able to do this, he goes on his own to look for it on his own. Upon encountering the beast, he is unable to kill him, thus sets him free. Meanwhile, his father recruits the dragon fighters to come with him to find their nest and destroy them once and for all. Hiccup stays behind and wanders off to the forest where he finds the creature unable to fly because he hurt his fin. After taming the creature he constructs a new prosthetic fin so that the dragon could fly because he also feels bad for crippling him.
During the process of taming the Toothless, he learns a thing or two about dragons. Thus, now he is the master of dragon training. When his father arrives not being able to find the dragon nest, he is delighted at his son’s success. Having passed the dragon training, he is now given the honor of killing a dragon. Instead, he subdues, a skill he learned earlier. His father does not like this and angers the dragon into attacking him when his friend dragon toothless tries to rescue him.
However, he is captured by the villagers, caged. Hiccup thinking might help tell his father that he knows where the dragon nest is. So they set off to find it and kill the big guy. When they arrive at the destination, they anger the big guy dragon “Red Dragon” and are almost defeated by him. Hiccup comes to their rescue with his dragons and friends. They kill that dragon and free the others. He gets his crush and is now a valued member of his society.