''How to Train Your Dragon'' is a successful, long-running children's book series written and illustrated by Cressida Cowell. It follows the adventures of the son of a Viking chief, Hiccup Horrendous Haddock the Third, as he struggles to keep control of his dragon and become a respected member of the Hairy Hooligan tribe.

Better than it sounds, it's got witty humor, [[GenreSavvy Genre savviness]], LampshadeHanging, clever dialogue and GettingCrapPastTheRadar. Thus, [[PeripheryDemographic teens and adults have found]] [[GuiltyPleasure a good read in them]].

The books in the series include:
#''How to Train Your Dragon''
#''How to Be a Pirate''
#''How to Speak Dragonese''
#''How to Cheat a Dragon's Curse''
#''How to Twist a Dragon's Tale''
#''A Hero's Guide to Deadly Dragons''
#''How to Ride a Dragon's Storm''
#''How to Break a Dragon's Heart''
#''How to Steal a Dragon's Sword''
#''How to Seize a Dragon's Jewel''
#''How to Betray a Dragon's Hero''

More books are likely to come, though it is hinted that the series is reaching its close. There is also a SpinOff called ''How to Train Your Viking'', which takes place between the second and third books told in Toothless's point of view. Hiccup and his father Stoick the Vast actually made their first appearance in a picture book called ''Hiccup: The Viking Who Was Seasick'', essentially making it a prequel to the main series. No dragons in that one, though.

It was recently given an incredibly successful film adaption by Creator/DreamWorksAnimation, with ex-Disney animator Chris Sanders (''Disney/LiloAndStitch'') at the director's helm. It is largely an InNameOnly adaptation, but most characters retain their book names. [[http://www.youtube.com/watch?v=qHUhygdAZIw Here's the trailer.]] Trope page for the film is '''[[WesternAnimation/HowToTrainYourDragon here]]'''.

Oh, and the audiobooks are narrated by Creator/DavidTennant.

!!!Characters from the book include:
* Hiccup Horrendous Haddock the Third - The son of the Viking Chieftain of the Hairy Hooligans. Although weedy and ordinary-looking, he's extremely intelligent and the OnlySaneMan.
** Toothless - Hiccup's dragon, named for his lack of teeth. He is very fussy and disobedient.
* Fishlegs - Hiccup's DeadpanSnarker best friend and an even more pathetic Viking than Hiccup. He's got a limp, poor vision, numerous allergies, and is easily scared.
** Horrorcow - Fishlegs' dragon. Docile and a vegetarian, she sleeps a lot.
* Snotface Snotlout - Second-in-line for the chief's throne and Hiccup's cousin, Snotlout is everything a Viking SHOULD be. He frequently tries to get rid of Hiccup so he may one day become the chief. [[spoiler: He succeeds in Book 9, courtesy of Alvin. Then gets KilledOffForReal in book 11.]]
** Fireworm - Snotlout's dragon. A brutal killer and easily provoked. She's every bit as smug and mean-spirited as Snotface.
* Stoick the Vast - The current Viking chief. Is a caring father but is dense and quick-tempered.
* Gobber the Belch - The head teacher of the Viking Initiation Program and the Pirate Initiation Program.
* Camicazi - Heiress to the throne of the Bog Burglars, Camicazi is a violent Viking girl who fights first and asks questions later. Friends with Hiccup and Fishlegs.
** Stormfly - Camicazi's dragon. A rare breed, she's a constant fibber and turns purple when she lies. One of the only dragons to speak Norse.
!!Tropes for the Books include:
* TheAce: Humungously Hotshot The Hero. He's good at everything (except singing). Deconstructed slightly and played for laughs when several members of the tribe, mainly Stoick, dislike him because he's better at everything than they are. Also deconstructed with Hiccup III's ancestors, Hiccup II and Grimbeard the Ghastly.
* ActionGirl: Camicazi.
** If we can infer anything from her and Bertha's description, what she says, and the [[spoiler:letter to Stoick from her]], the entire Bog Burglar tribe somehow seems to be made up completely of women]]. Cressida Cowell has confirmed on Twitter that the male Bogs are part of a tribe called the Silents.
* AffablyEvil: The Green Death.
* AGodAmI: Ziggerastica, the tiny nanodragon, believes himself to be the center of the universe. However, due to his uncanny abilities, including being able to come when called, no matter how far away, makes you wonder...
* AlliterativeName: Too many to count. There's just about everything from names ("Hiccup Horrendous Haddock" the Third) to a good portion of the Viking Tribes ("Bog Burglars") to even the names of celebrations ("[[PunnyName Thor'sday Thursday]]"). Also, the text itself is FILLED with alliterations - strings of five or six words starting with the same sound are not uncommon. It's especially obvious in the audiobook version of the series.
* ArbitrarySkepticism: The kids have tamed dragons, and Camicazi even has one which speaks some Norse... But mermaids are just fairy tales that can't possibly be real.
* AwesomeMcCoolname: Some of the names fall into this, such as "Humungously Hotshot the Hero". Abbreviated: "Humungous".
* AnAxeToGrind: Norbert the Nutjob's ''fricking huge axe.''
* AxCrazy: Norbert the Nutjob is perhaps the best example in fiction.
* {{Badass}}:
** Several of the different breeds of dragon. Namely the Sharkworms and the Saber-Toothed Driver Dragons.
** Many of the human characters would count, as so, so many are incredibly skilled fighters. Hiccup in particular, as he [[spoiler: won the free-for-all sword fighting competition; trained a Seadragonus Giganticus Maximus, an untrainable species, to be so loyal to him that it overcame red rage; and killed two mountain-sized dragons, by blowing up one and electrocuting the other]].
* BadassAdorable: Camicazi and Ziggerastica.
* BaitTheDog: Played straight in Alvin the Treacherous's first appearance, where he poses as Poor but Honest Farmer and even encourages Hiccup during a fencing lesson. Later, when he, Hiccup and Fishlegs [[spoiler: barely escape drowning and end up in a cave miles below the ocean's surface]] he becomes charming and apologetic [[spoiler: until they find a door and Grimbeard's treasure.]]
** ZigZagged with Humongous the Hotshot in ''How to Twist a Dragon's Tale''; he [[spoiler: keeps trying to kill Hiccup while posing as his bodyguard]] but cannot overcome his hero instincts.
* BeautyEqualsGoodness: Mostly averted. None of the characters are actually that pretty, with the exception of Humungously Hotshot the Hero, and [[spoiler:Alvin, who seems to be getting uglier each book.]]
* BerserkButton: In ''How to Be a Pirate'', [[spoiler:Fishlegs]] discovers that he's a berserker. When he [[spoiler:catches a cold]] in ''How to Cheat a Dragon's Curse'', he sometimes [[spoiler:involuntarily went berserk.]]
* BigBad: Usually [[spoiler:[[MagnificentBastard Alvin the Treacherous]]]]. Also: The Green Death, Norbert the Nutjob and Furious.
* BoisterousBruiser: The Viking tribes seem to made entirely out of boisterous bruisers.
* BreakTheBadass: Excellinor tries to do so to [[spoiler:Hiccup in Book Eleven so as to convince his followers to join her side. It doesn't work, in part because Hiccup had a backup plan.]]
* BreakTheCutie: Again, Hiccup throughout the series, as part of his journey to becoming a Hero the Hard Way. Same thing happens to Camicazi and Fishlegs, since they are Hiccup's TrueCompanions.
* BrickJoke: In one of the last remaining chapters of the original novel ''How to Train Your Dragon'', Stoick is furious over a book by Professor Yobbish called ''How to Train Your Dragon'' that is only one page describing that the best way to train dragons is to "yell at them" he declares that he is going to send Yobbish a strongly worded letter. The letter, poorly spelled, shows up as a picture prefacing the Epilogue.
* CainAndAbel: Subverted with Stoick and his brother Baggybum the Beerbelly. While they initially butt heads over whose son would make a better ruler, when things get rough they stand [[BackToBackBadasses back to back]]. Played straight with Hiccup's ancestor Hiccup II and his brother Thugheart, and with Hiccup and his cousin Snotlout.
* CallingTheOldManOut: In the first book, Hiccup calls out Stoick for [[spoiler:banishing all of the Initiates and placing the Law over the life of his own son. Does the same to his mother for seemingly betraying him to Alvin the Treacherous and the witch, though YMMV on if it's a subversion]]
** Inverted when Baggybum and Gobber call out Snotlout for [[spoiler: betraying their tribe and Hiccup, selling out people who depend on him. Gobber later leads the Dragonmarkers in turning their backs on Snotlout in Book Eleven.]]
* CerebusRetcon: When the Hooligan tribe encounters Grimbeard the Ghastly's booby traps while searching for his treasure in ''How to Be a Pirate,'' the reader assumes that Grimbeard merely had a nasty sense of humor. Then in ''How to Break a Dragon's Heart'' and ''How to Betray a Dragon's Hero'' Hiccup and the reader learns that Grimbeard [[spoiler: created slavery for dragons and humans alike, turned the Dragonmark into the Slavemark, murdered his son Hiccup II believing him to be a traitor, and left the Archipelago in the state that it was]].
** Also, in ''How to Be a Pirate'' Alvin jokes that he has no hope for redemption because his mother never loved him. [[spoiler: Then we meet his mother in ''How to Break a Dragon's Heart, and we realize he is right in that she loves no one. Even Alvin is terrified of her.]]
* CharacterDevelopment: All the characters, heroes and villains alike, change over the course of the series. Hiccup grows from a brilliant if cautious ten-year old to potential King of the Wilderwest and expert Dragon Whisperer. Alvin the Treacherous becomes more dangerous and DangerouslyGenreSavvy, thanks to his mother Excellinor.
* ChekhovsGun: Too many to count. Some of the King's Lost Things [[spoiler: Grimbeard's second-best sword Endeavor, the Roman shield, the Hysteric key that opens everything, Toothless, Grimbeard's "ticking thing," the heart's stone that contains a ruby]]. Others to note: [[spoiler: Hiccup's Slavemark and Norbert's flying machine]], in ''How To Ride A Dragon's Storm'' and [[spoiler: Fishlegs's lobster pot]] in ''How to Seize a Dragon's Jewel'']].
* ChekhovsGunman: Valhallarama of the White Arms, Hiccup's mother, and the Hairy Scary Librarian in Book Ten.
* ChronicBackstabbingDisorder: Dragons are supposed to be this way, but they subvert the trope on occasion. [[spoiler: Snotlout plays the trope straight; becomes a plot point in Book 11.]]
* ChildProdigy / TeenGenius: Hiccup, at least compared to everyone else. His friends are smarter than the average Viking but are more of a case of OnlySaneMan.
* CoolSword: The Stormblade.
* CouldHaveAvoidedThisPlot: Arguably, ''How to Betray a Dragon's Hero'' because of the choices that Hiccup makes.
** The whole quest to find the Lost Things and crown a new King of the Wilderwest happened because Grimbeard the Ghastly crossed the DespairEventHorizon and dismantled his kingdom, creating a prophecy for a new, worthier King to take his place. [[spoiler:According to the Wodensfang, Grimbeard was the first Hooligan to turn the Dragonmark into the Slavemark, and to enslave humans and dragons while building his empire, [[TheCaligula while a]] [[TyrantTakesTheHelm teenager]]. The Dragon Jewel gave Grimbeard power over all the dragons, and thus he could have used it and the power from his empire to end the slavery that he had created, and he could have killed his son Thugheart, Alvin the Treacherous's ancestor, instead of exiling him.]]
* CrapsaccharineWorld: The Viking Archipelago. Sure it has dragons, but it also has established slavery, murderous Vikings, and [[ArsonMurderAndJaywalking limpets!]] No wonder Hiccup decided to change things when he could, by becoming King of the Wilderwest
** What's worse is that the Vikings who thrived in this world have to deal with it shooting up into flames thanks to [[spoiler: Hiccup releasing Furious and freeing the dragons during his short bout as King]]. Some adapt, but others like [[spoiler: Snotlout]] don't.
* CreateYourOwnVillain: Inverted here. [[spoiler: By breaking up Humongous Hotshot and Valhallarama so she would marry Stoick the Vast instead, Alvin inadvertently helped bring Hiccup into existence. Karma's a bitch, isn't it?]]
** Played straight with Furious. By killing Furious's human brother Hiccup II and leaving Furious to rot in chains, Grimbeard the Ghastly created a WoobieDestroyerOfWorlds who wants to kill Grimbeard's heir.
* DarkerAndEdgier: In general, more so than the film adaptation in that Hiccup faces carnivorous dragons and murderous Vikings and nearly dies once a book. In ''How to Train Your Dragon'' the Green Death [[spoiler: eats him alive]] and in ''How to Be a Pirate'' Skullions chase him down during the hunt for Grimbeard's treasure.
** ''How to Twist a Dragon's Tale'' ventured into this territory quite a few times, but it gets back to normal in ''A Hero's Guide to Deadly Dragons''.
** ''How to Steal a Dragon's Sword'' is considerably darker than the previous light-hearted books. [[spoiler: Everyone turns their backs on Hiccup when his slavemark is revealed when Snotlout threw a rock to the helmet and had believed that they should have abandoned Hiccup. Stoick was banished. Alvin the Treacherous ruled as King of the Wilderwest and made Snotlout the new Hooligan chief.]]
** ''How to Seize and Dragon's Jewel'' and ''How to Betray a Dragon's Hero'' up the ante for darkness: [[spoiler: Hiccup finds the titular jewel but loses it to Alvin in a fit of bad luck, his cousin Snotlout betrays him to Alvin AGAIN and causes him to lose Toothless before getting KilledOffForReal in a moment of RedemptionEqualsDeath. Hiccup has only twenty-four hours to convince the Guardians of Tomorrow to crown him king, without any of the Lost Things and with the Wodensfang ready to betray him to the dragon Furious. Hiccup confirms that he will face the murderous Guardians of Tomorrow and Furious in the last book]]
* DarkestHour: [[spoiler: The end of ''How to Betray a Dragon's Hero.'' Hiccup confirms in the prologue that the next two books cover the darkest part of the series, and that they were the most difficult to chronicle.]]
* DeadpanSnarker: Fishlegs is a definite candidate.
---->'''Fishlegs:''' Oh, how I wish ''I'' had a nice smart Bardiguard all of my very own, to chuck rocks at me, and send me unarmed into one-to-one combat with teenage psychopaths.
** Hiccup dabbles in it several times, as do most of the dragons.
* DenserAndWackier / LighterAndSofter: After TheFilmOfTheBook was released, the books took a major shift in terms of cover art and art direction in general, making the covers more cartoony. The dragon profile pages also became simpler, instead describing only "disobedience" and "attack", "defense" and "speed". The actual content of the stories, however, has ''[[DarkerAndEdgier not]]'' suffered from this, fortunately.
* DespairEventHorizon: Hiccup nearly crosses it in Book Four when [[spoiler:he fails to deliver the curative potato to Fishlegs, who is supposedly dying from Vorpentitis]]. Grimbeard the Ghastly crossed it eons ago when [[spoiler:he killed his favorite son Hiccup II after mistakenly believing him to be a traitor, and had to banish another, Thugheart for actually betraying him.]]
* DudeWheresMyRespect: Hiccup. He saves the day several times and Snotlout usually gets credit for it all.
** Not quite. Most of the time, the books end with a CrowningMomentOfHeartwarming where Hiccup and Fishlegs end up getting celebrated for what they did, but the problem is [[StatusQuoIsGod they always end up getting mocked again, usually thanks to Snotlout]] [[AesopAmnesia by the next book]]. ''How to Be a Pirate'' even [[LampshadeHanging lampshades]] this in the opening scene.
** Changes after ''How to Seize a Dragon's Jewel.'' [[spoiler: Thanks to Alvin [[NiceJobFixingItVillain being a slave-making tyrant]] and Hiccup's heroic deeds from the previous books getting acknowledged during the year he's in exile, all the slaves at the Prison Darkheart and free heroic Vikings like Thuggory rise up to support Hiccup as King of the Wilderwest. When Excellinor tries to break Hiccup in ''How to Betray a Dragon's Hero,'' she accidentally makes him more heroic when he endures her torture in front of his followers.]]
* DumbMuscle: Most of the adult Vikings in the story, actually.
** ...As well as several of the younger tribe members.
** And the Driller Dragons.
* EarnYourHappyEnding: Hiccup in the prologue and epilogue of each book explains that his memoirs explain how he became a hero "the Hard Way" and several epilogues have shown how things got better in terms of curing Vorpentitis and repairing his relationship with his mother. We readers do know that he survives [[spoiler: the Island of Tomorrow and its guardians, Alvin the Treacherous and Excellinor's scheming, the Sea Dragon Furious who believes Hiccup will end the world of dragons]]. [[spoiler: Also that even if the dragons disappear, [[CrowningMomentOfHeartwarming Toothless stays with him.]] ]]
* EasilyForgiven: Hiccup does this with Snotlout all the time in Book Eleven, even after [[spoiler: Snotlout betrays him to the witch]]. It's lampshaded by the other characters, including Fishlegs and Snotlout himself.
* EldritchAbomination: Seadragonus Giganticus Maximus. They're constantly described as being big as cliffs and hills, and their smallest teeth are ''8ft long''.
* EyelessFace: Skullions
* FailOSuckyName: Quite a few characters, although Fishlegs, Baggybum the Beerbelly, Clueless, Lardtummy Low-Watt, and Loudmouth the Gouty are some of the worst.
* FictionalDocument: There is a book in ''How to Train Your Dragon'' that literally shares the title.
** Hell with it, there's also the book ''How to Speak Dragonese'' WITHIN the book of the same title. And ''A Hero's Guide to Deadly Dragons'' in ''A Hero's Guide to Deadly Dragons.''
** There's also the letter Grimbeard the Ghastly wrote to "his heir", more commonly known as [[spoiler:Hiccup Horrendous Haddock the Third. That document is also a map to find the Dragon's Jewel]]
* EvilMatriarch: Excellinor the Witch, mother of [[spoiler: Alvin the Treacherous]]. When her son becomes King she seems to be leading him.
* GagBoobs: [[ExactlyWhatItSaysOnTheTin Big-Boobied Bertha]]. Jesus Christ.
* {{Gainaxing}}: Book 7 gives us a scene of this with Big-Boobied Bertha.
* GettingCrapPastTheRadar: Not even a legitimate attempt to get it past the radar. Apparently, the Dragonese word for "poo" is "crappa". The word for "toilet" is "crapspot".
** ''Everything'' about "''[[GagBoobs Big-Boobied Bertha]]''". Yeah.
** They used the word "hell" once, in ''How To Cheat A Dragon's Curse''. Not normally a big deal in most {{literature}}, but it's notable when it's in a book written for 8-12 year olds.
** Berk is a British slang word meaning idiot/{{Jerkass}}, derived from Berkshire Hunt, which is cockney rhyming slang for CountryMatters.
* GiganticAdultsTinyBabies: [[spoiler: Toothless is a young Seadragonus Giganticus Maximus, given time, he will grow to the ''size of a mountain.'']]
* [[LoveDodecahedron Hate Dodecahedron]]: The blood feud table:
** The Outcasts are feuding with everyone because of an attitude problem.
** The Bog Burglars are feuding with the Hooligans because of theft, the Rashem Oiks because somebody knocked over Bertha's pint, The Hysterics because Bertha sat on the chief's dragon, The Visithugs because Bertha laughed at Visithug axework, and The Ugli-Thugs because of sheep-rustling.
** The Hooligans are in feud with the Meatheads because Stoick beat Mogadon in a arm-wrestling contest.
** The Meatheads are in feud with the Rashem Oiks because they just don't like each other.
** The Hysterics are in feud with the Visithugs because an arm-wrestling contest went a little too far, and with the Ugli-Thugs because Ugli-Thugs are nasty pieces of work.
** The Rashem Oiks and Ugli-Thugs are feuding because... who are you looking at, sunshine?
*** Yes, some of these are very sensitive - particularly Bog Burglars vs Rashem Oiks and Bog Burglars vs Visithugs (in that order).
* GrowingUpSucks: The prologue to one of the later books in the series apologises for the CerebusSyndrome the reader is about to hit, but points out that the books are ultimately about growing up and the difficulties that entails. They then point out that even the (assumed child) reader is going to become an adult, whether they like it or not. The tone of the prologue makes it clear that the narrator believes that everyone would avoid growing up if they could.
* HeelFaceRevolvingDoor: Snotlout.
* HeelRealization: Again, Snotlout, [[spoiler: after the witch invokes a HeelFaceDoorSlam on him that doesn't take.]]
* HeroesPreferSwords: Hiccup does, as do Camicazi, Stoick, Snotlout, Humongously Hotshot, and Valhallarama.
* {{Homage}}: [[spoiler:The end of ''How to Cheat a Dragon's curse'' resembles the ending of {{Gilgamesh}}.]]
* Hope Spot: The later books show various occasions of this. [[spoiler:In Books 8 and 9, Hiccup has one about Furious choosing to not annihilate the humans, and then to become King of the Wilderwest so as to prevent a war between dragons and humans. Book 10 is a Hope Spot when Valhallarama rallies followers for Hiccup to become King, and for her the quest to crown Hiccup offers her the chance to repair her relationship with her son. As is common in the series, each of these hopes gets dashed rapidly.]]
* HornyVikings: This takes place amidst several fictional Viking tribes, such as the Hairy Hooligans, Murderous Meatheads, and Bog Burglars.
* HorsingAround: Toothless, in a non-horse example.
* IdiotBall: Hiccup carries it in ''How to Betray a Dragon's Hero'', though he tries to avoid it. [[spoiler:Suspecting that Snotlout will betray him to Alvin, he creates a backup plan with Fishlegs but doesn't think to give Toothless, the last Lost Thing, to Fishlegs for safekeeping. As a result, Alvin obtains all the Lost Things, including an unwilling Toothless, and will be crowned on the Island of Tomorrow unless Hiccup can reach him in 24 hours.]]
* ImAHumanitarian:
** Dragons seem to do this, with some enjoying snacking on nanodragons (enjoyed by humans and dragons alike) and [[spoiler:the Green Death eating his smaller companions when they get washed ashore.]]
** The Outcast Tribe does this but only with the chief of a village and his heir.
* ImprovisedWeapon: A rather strange example of this trope occurs in ''How To Twist A Dragon's Tale''. When dueling [[spoiler:Alvin the Treacherous]], Hiccup uses various implements from Fishlegs's Running-Away Suitcase, including tooth powder and and umbrella as a sword. When [[spoiler: Alvin]] about to do away with Hiccup, once and for all, Hiccup [[spoiler:''bursts into song'']]. This surprises [[spoiler:Alvin long enough for Humongously Hotshot to rescue Hiccup]].
* ILied: Alvin the Treacherous and his mother Excellinor do this all the time. Most Vikings catch on quickly after being betrayed once or twice. [[spoiler: Snotlout doesn't.]]
* InstantAwesomeJustAddDragons: Obviously.
* InstructionalTitle
* JerkAss: All untamed dragons. Human examples: Snotlout, his dragon and his cronies.
* JerkJock: Snotlout.
* KnightOfCerebus: The dragon Furious, who wants to wipe out all humans, and [[spoiler: the witch Excellinor]].
* LargeHam: Gobber and Stoick the Vast.
* LaserGuidedKarma: In ''How to Cheat a Dragon's Curse.'' Hiccup spends much of the book on a quest to save Fishlegs, who, according to Old Wrinkly, the soothsayer, is dying from the bite of a poisonous dragon. [[spoiler:Guess who had really been bitten.]]
** A more subtle example happens in ''A Hero's Guide to Deadly Dragons.'' In that book, Hiccup [[spoiler: sells the Hairy Scary Librarian into slavery to save Big-Boobied Bertha from Madguts the Murderous. In the very next book, Hiccup received the Slavemark through a series of random events, and it dogs him for the rest of the series. Hairy also gets his revenge in ''How to Seize a Dragon's Jewel.'']]
* LavaSurfing: Done in ''How to Twist a Dragon's Tale''.
* MamaBear: All the mothers in the book; there is even a Wanderer called "Bear-Mama""
* ManipulativeBastard: Excellinor the Witch, mother of [[spoiler: Alvin the Treacherous]], is able to make her son King of the Wilderwest through her scheming.
* MeaningfulEcho: "Isn't Fate ''artistic?''"
* MeaningfulName: [[DumbMuscle Dogsbreath the Duhbrain]], [[spoiler:[[ManipulativeBastard Alvin the Treacherous]]]], [[GagBoobs Big-Boobied Bertha]], [[AxCrazy Norbert the Nutjob]], [[TheAce Humungously Hotshot the Hero]], [[TheBigGuy Stoick the Vast]], and, of course, Toothless.
* MiseryBuildsCharacter: The book series' running theme, and invoked in the epilogue of ''How to Betray a Dragon's Hero.'' Despite that book having [[spoiler: a DownerEnding and DarkestHour moment, Hiccup as an old man asserts that his younger self needed to go through that ordeal to become a proper Hero.]]
* MissingMom: Valhallarama, Hiccup's mother. She briefly appears in ''How To Train your Dragon''...only to promptly disappear for a couple of books, until it's revealed she's off questing. Reappears in Books Ten and Eleven
* MonsterOfTheWeek: Each book introduces a new and deadly dragon.
* MysteriousPast: Most notably [[spoiler:Alvin the Treacherous]], but several other characters have mysterious pasts as well.
* NamesToRunAwayFromReallyFast: A name like Norbert the Nutjob is a pretty good tipoff to what the character's actually like.
** [[spoiler:Alvin the Treacherous]].
* NiceJobBreakingItHero: In-universe, Hiccup releasing the Dragon Furious since it starts a war between dragons and humans. Plenty of Vikings, including his father and Snotlout, are upset about that.
** Hiccup also [[spoiler: released the witch from her tree prison]]] by accident, but only Alvin called him out for that.
** Hiccup accidentally losing [[spoiler:Toothless and the Dragon's Jewel to Alvin in two different books, giving his worst enemy all the Things needed to become King of the Wilderwest.]]
* NiceJobFixingItVillain: Excellinor's ReasonYouSuckSpeech to [[spoiler:Snotlout]] in Book 11 [[spoiler:spurs him to a HeelRealization and eventually join Hiccup's side.]]
* NinjaPirateZombieRobot: Sharkworms, which are dragons that resemble hammerhead sharks with legs ''and'' wings.
** Saber-Toothed Driver Dragons.
* NoOneCouldSurviveThat: Hiccup, at least [[OnceAnEpisode once a book]]. Same with Alvin and the witch.
* OnlySaneMan: Hiccup, as well as Fishlegs and Old Wrinkly when they're around.
* OurDragonsAreDifferent: The majority of the dragons in this series are either small and trainable or monstrously huge and primeval. Not to mention, the author comes up with her own breeds of dragons.
* PoorCommunicationKills: Valhallarama and Hiccup in Books Ten and Eleven. Justified in one instance, where [[spoiler:Valhallarama has been ordered to kill the the enemy of the Wilderwest without knowing that it's Hiccup, and Hiccup can't tell her to stop fighting because his helmet gets jammed during their fencing duel.]] In Book Eleven, [[spoiler: she just tells Hiccup to seek refuge in a Hideout until the Doomsday of the Yule, and doesn't explain her plan to obtain the Lost Things. As a result, when Hiccup decides to trust Snotlout and steal the Lost Things on his own, he accidentally interrupts Valhallarama's plan. [[JustifiedTrope Justified]] in that there's no reliable source of communication during the war.]]
* ProphecyTwist: at the end of ''How to Cheat a Dragon's Curse''. Hiccup has been on a long journey to save Fishlegs, who, according to soothsayer Old Wrinkly, has Vorpentitis. Except it turns out that [[spoiler: "one little weirdo looks very like another when you're soothsaying in a fire" -- Hiccup has it, not Fishlegs.]]
* ProudWarriorRace: The Vikings, obviously.
* RebelliousPrincess: Camicazi to her mother. (She's technically the heir to her tribe, so this counts.)
* ScaryLibrarian: The Hairy ScaryLibrarian.
* ScrewTheRulesImDoingWhatsRight: Hiccup, in ''How to Cheat a Dragon's Curse''. He disobeys his father, the Chief, to save Fishlegs.
* ScrewTheRulesIMakeThem: Snotlout does this at the start of ''How to Train Your Dragon''.
* SeriesContinuityError: In the first book, there were 10 Viking students for the Hairy Hooligans. Somehow in the next book this number got raised to 12 and has been that way ever since.
** New ones joined, then.
* SmugSnake: Snotlout and his dragon, Fireworm.
* SneezeOfDoom: Happened twice in the first book; Fishlegs does one in the beginning [[spoiler:...actually four, waking all the dragons in the dragon nursery and necessitating a hasty escape]] and the Green Death does one at the end. [[spoiler:Because he swallowed Hiccup, Toothless flies up his nostril and causes him to sneeze him out]].
* SpeechImpediment: Toothless stutters a lot. Vorpentitis also causes facial muscle paralysis, inducing this.
* StaringDownCthulhu: Hiccup has trained himself to hold a dragon's gaze. He even does this with a three-headed dragon in book 10, although who actually wins is open to debate.
* StatusQuoIsGod: Doesn't matter what kind of spectacular feats Hiccup has performed, by the beginning of the next book, he's back to being everyone else's ButtMonkey. This is usually because of Snotlout's bullying. Changes after Book 9.
* StayingAlive: [[spoiler: Alvin the Treacherous]]. He keeps cheating death again and again and again...losing bits and pieces of himself each time. Same with Hiccup, although his limbs remain intact. {{Lampshaded}} several times.
* StickyFingers: Camicazi and her entire tribe.
* {{Stripperiffic}}: Gobber's standard outfit, which consists of a sleeveless [[BareYourMidriff bellybutton showing]] shirt and hairy short-shorts.
* StylisticSuck: The drawings within the book.
* SurroundedByIdiots: Vikings are great, big and muscly, but they don't have a lot going on in the brains department, which means Hiccup and Fishlegs are usually the [[OnlySaneMan only sane men around]].
** Fishlegs even {{lampshades}} this once or twice.
* TalkingAnimal: Stormfly can speak Norse, and pretty much all of the dragons can talk (though only Hiccup is fluent enough in Dragonese to understand them). [[spoiler:So can the Wodensfang and Furious.]]
* ToiletHumour: No less than once a book, sometimes with [[{{Squick}} illustrations]]. Thankfully it gets less gross as the series goes on.
* TheChosenOne: Grimbeard the Ghastly states in a letter that [[spoiler:his heir would be the one to uncover his massive treasure]]. Which is [[spoiler:Hiccup.]]
** Well [[spoiler:Hiccup]] was his [[spoiler:great-great grandson]].
* TheScottishTrope: The Vegetable That Must Not Be Named, aka a [[spoiler:potato.]]
* {{Tomboy}}: Camicazi.
* {{Tsundere}}: Camicazi, to an extent.
* UnexplainedRecovery: [[spoiler:Alvin the Treacherous]], all the time.
* UngratefulBastard: The dragons are this, and they're proud of it. Eventually they admit that they're ''hardly ever'' grateful. This trope is Lampshaded when applied to Alvin and his mother Excellinor. Snotlout PlaysWith the trope.
* UrineTrouble: Toothless in the first book. In the kitchen, on Hiccup's hands and down his shirt ... [[NauseaFuel except with poo]].
* VillainousBreakdown: [[spoiler:Norbert has one at the end of the 7th book.]]
* WaterWakeup: A variation in ''How to Cheat a Dragon's Curse''; Fishlegs "[takes] a bucket of snow and [throws] it in Stoick's face."
* WeaponOfChoice: Hiccup and Camicazi both wield swords.
** Also Norbert and his axe.
** The Hairy ScaryLibrarian's twin swords.