Personality
Despite his physical shortcomings, Hiccup does his best to succeed as a Viking. He is smart and is constantly creating inventions for various uses throughout the film, including a bola sling, a prosthetic tail, a saddle, and a riding vest. At first, however, Hiccup is almost obsessed with proving himself to the rest of his tribe; he often doesn't think things through and is more determined to gain the recognition of his peers than he is heedful of others' orders, often causing problems for the rest of the tribe, and himself. Despite this, Hiccup shows great aptitude at being a leader and a strategist: he leads his Dragon Training classmates into battle, using his friends' strengths wisely in the battle against the Red Death. Hiccup also has very good observational skills which come in handy during his time with Toothless and during Dragon Training. For example, he's able to hypothesize that Dragons have a natural disdain for eel when his own Dragon companion refuses to eat one himself, and uses this to successfully drive back a Hideous Zipplebacklater.
Among the other teenage Vikings, Hiccup first comes off as awkward, mainly because he's a poor fighter, and rather scrawny for a Viking. As he becomes more adept at fighting Dragons, however, they start paying more attention to him, some even starting to try to talk to him first. Despite this, Hiccup remains shy and secretive, preferring to be alone with Toothless, likely because he's unused to all the positive attention. He also tends to be sarcastic with a dry sense of humor that can sometimes put him at odds with the other Vikings in his tribe. It also seems that Hiccup likes to hide his fear, hurt, or sadness with said sarcasm and dry humor. Due to his shyness he had a habit of stuttering and stammering when talking to some of the other Vikings, especially Astrid or when his father was angry at him. Despite his many virtues and his clear capabilities as a leader, Hiccup is not without his flaws. He is rather prone to letting his insecurities cloud his judgement and effect his actions; in the film, his desperation for the acceptance of his tribe, and his father in particular, cause him to regularly try to kill dragons along with them, only to end up doing more harm then good due to his clumsiness. In the television show, his mistaken belief that Stoick still does not accept him causes him to lead the other Vikings on a potentially dangerous treasure hunt to prove himself. His innate friendliness and tendency to give others the benefit of the doubt cause him to be a little too trusting of strangers, leaving him vulnerable to manipulation and deceit by more dishonest characters, such as Heather and Mildew, on more then one occasion. In the episode "Thawfest", Hiccup shows a more unlikable, competitive side of his personality as he begins to score victories over Snotlout. Since Hiccup is unaccustomed to winning anything, he handles it very badly, letting the glory go to his head to the point where he becomes just as arrogant and unpleasant as Snotlout. However, in spite of all his flaws, Hiccup is never above admitting when he is or has been in the wrong, and will do his best to make amends.
One extremely notable character trait Hiccup possesses is a deep sense of compassion. Because of this he spares Toothless, and in doing so he changes the world of How to Train your Dragon forever. He was extremely uncomfortable with the thought of having to kill a Dragon in the arena later in the film. Hiccup carries this quality into the television series. He shows great sympathy to Snotlout at the end of the Thawfest games, giving up his own glory and fame for the sake of his friend. He will almost never allow Toothless to use his full power against foes. He begs Toothless to spare a Whispering Death that had nearly killed both of them just moments earlier. The peak of Hiccup's sympathy is displayed in his releasing Mildew, the very man who had betrayed him, from an Outcast cell. Upon seeing the Outcasts take Mildew's one beloved possession, his sheep, Hiccup clearly displays pity for the old man. Unfortunately Hiccup is occasionally naive in his sympathy, for Mildew would soon betray him yet again. Still his kindheartedness has resulted in many a victory and accomplished the training of the most deadly dragon on the planet. The one character Hiccup seems to be willing to attack and even kill is Alvin. Originally he was more interested in avoiding him, but as Alvin's plots hit closer and closer to everything Hiccup cares and hopes about, Hiccup seems to harden in a difficult resolution. He has been seen ordering Toothless to kill Alvin when Alvin was threatening to toss Astrid off of a cliff. In the finale, Hiccup and Toothless both even charged Alvin in an attempt to kill him after he had captured, threatened, and deeply insulted both of them. They failed in this attempt, but with Alvin being one of the few people Hiccup is willing to let Toothless kill, Alvin may want to watch his step. Overall Hiccup is a smart, nice and a likable person who is naturally bighearted and innocent. It's also shown in the sequel that he and Toothless have become, what Dean Deblois calls "adrenaline junkies", performing tricks like free-falling while flying.
