is the son of stoick the vast and valka

— Valka

Between fourteen and fifteen years before the events of the first film, Hiccup was born prematurely to Stoick the Vast and his wife Valka. Although the new mother was worried that Hiccup would not survive his early birth, Stoick was confident that he would grow strong and Hiccup did indeed prosper. At his birth, Hiccup was given a small axe by Stoick, so he could start training immediately, much to his mother's chagrin. However, Stoick claimed that Hiccup used the axe as a paperweight. When he was still a baby, Valka sewed Hiccup a dragon toy with his name stitched into the sides. Gobber made the baby diapers.

One night during a dragon raid, a Stormcutter dragon broke into their house, finding baby Hiccup in the cradle. Valka rushed to his rescue, but found the dragon curiously playing with Hiccup, leaving the baby giggling in delight, proving that everything that Valka believed about dragons was true. The Stormcutterwas startled when he noticed Valka's presence, accidentally scratching Hiccup's chin with a wing claw when he turned to look in her direction. Hearing the baby crying, Stoick rushed to the scene. He and the dragon started fighting with each other, resulting in the house being burned and Valka being abducted by the dragon, leaving Stoick to raise Hiccup alone. This experience left Hiccup with a deep fear of dragons, so much so that while he was still very young, he threw the dragon toy his mother made for him into the ocean one day when he and his father were out fishing.

After what happened to his wife, Stoick became overprotective of his son, while Valka decided to spend the rest of her life away from Berk, fearing that her love of dragons might harm those she cared most about, including Hiccup. It was understood that she had been eaten by a dragon. So this was the belief that Hiccup grew up with.

When Hiccup was about five, Stoick told his son about Berk and how Hiccup would someday be the chief of the island. He also told him about the Hidden World; a place where dragons lived at the edge of the world, and how he promised to find it and bring an end to the conflict between dragons and Vikings.

About a year after hearing about the Hidden World, Hiccup woke up one night and attempted to sneak downstairs to get a drink. He was surprised to find his father sitting in front of the fire weeping. He awkwardly headed back upstairs, but Stoick heard him and invited his embarrassed son to join him beside the fire. The boy happily jumped to the floor and onto his father's lap. Suspecting the reason he had been weeping, Hiccup gently asked if they were ever going to get a new mom. Stoick lovingly hugged and kissed the child, and explained that he didn't want another. He went on to offer a lesson in love and loss, and how it's a part of life. But there's no greater gift one can give than love.

Hiccup also grew up learning life lessons in games such as board games. One day while playing with his father, he excitedly jumped at an opportunity to get ahead, while over looking a weakness he was leaving exposed, leading to Stoick winning the game. The boy pouted in disappointment, while Stoick reminded him to always think carefully before he takes drastic measures.

Some years afterward, Hiccup and his father were walking through the woods of Berk, while Hiccup pretended to slay dragons with a toy sword as they went. They came upon an injured baby bird on the ground. Concerned for the animal, Hiccup asked what was wrong with it, and Stoick explained how it must have fallen out of its nest and broke its wing. Stoick instructed Hiccup to go ahead on the trail so he didn't have to witness the bird being put out of its misery, but Hiccup protested. He started to cry and begged his father to spare it, given it's so small and helpless. Moved by his son's tears, Stoick told Hiccup to fetch him a small twig. Once the boy brought a twig, Stoick pulled a hair from his beard and, having Hiccup gently hold the bird, used it to secure the twig to the bird's injured wing. He then told his son that the bird was his responsibility now, and he had to feed and care for it until it was well enough to fly on its own. The boy grinned in gratitude, and promised he would.

At Snoggletog time, he grew up performing in a pageant with many of the other village children. He thought they were fun unless his father was involved, because he'd be a little too good at acting out violent scenes, which would scare the young boy. Along with the other children, once he reached a certain age, he opted to join the adults in the audience rather than perform.

Hiccup grew slowly, remaining much smaller and weaker than other Vikings well into his adolescence. At a young age, Stoick enlisted him as Gobber's smith apprentice in hopes of both bulking him up and teaching him some discipline. By age eleven, Hiccup had become a laughing stock to his peers, resulting in him vowing to get revenge once he became chief. But his father reminded him that a leader doesn't seek revenge, and makes decisions best for the tribe, no matter how painful those decisions might be.

Despite being overprotective of him, by the events of the first film, Stoick began harboring feelings of shame toward his son. He complained had the attention span of a sparrow and would rather hunt for trolls than spend quality time with his father. He started referring to him as the worst Viking Berk had ever seen. Stoick even started using Hiccup as a pawn with other villagers, threatening them with watching him if they didn't join their chief in his mission. Such behavior led to a complex rift between the father and son by the time he was fourteen. Hiccup learned a lot being Gobber's apprentice, however, and soon began inventing contraptions of his own.