[[http://www.fanfiction.net/s/2760303/1/The-Best-Seven-Years The Best Seven Years]] is a crossover between ComicStrip/CalvinAndHobbes and Literature/HarryPotter, written by Blu Taiger. Several years after the comic strip, Calvin and his family has moved to England, when one night Susie arrives to visit Calvin while she is visiting her grandmother. Calvin then reveals what has happened since (the initially skeptical) Susie last: Calvin is a wizard.
A prequel story was written called ''[[http://www.fanfiction.net/s/5382850/1/In-Love-and-War In Love and War]]''. Taking place while Calvin and Susie were still classmates in the fourth grade, Calvin and Susie use Calvin's cardboard box time machine to travel back in time to research an oral history report. However, something goes wrong during their journey and they wind up during the war between the [[WesternAnimation/BeastWars Maximals and Predicons]], and must find a way home.
!!The fanfics have the following examples:
* AnalogyBackfire: While Merlin is making a time machine out of Calvin's mother's car, Hobbes replies that the only thing missing is for [[Franchise/BackToTheFuture an old man shouting "Great Scott!"]] Merlin's responce?
-->'''Merlin:''' "I have seen the Scots. They are not so great."
* AstralCheckerboardDecor: Several cardboard boxes fall face down from the sky in Susie's dream in ''In Love and War''. Their bottoms are black and white, and after they are finished falling make a gigantic checkerboard pattern.
* BigDamnHeroes: Galaxoid and Nebular bail Calvin out before he is sent to Azkaban.
** [[spoiler:Natalie saves Calvin's life by taking the Avada Kadava curse meant for him]].
** Calvin sneaks into the Predicon base to resque Susie, but is ultimately [[SubvertedTrope subverted]] due to being caught by Waspinator.
** The Maximals also pull one off after Calvin tries to rescue Susie.
* BeethovenWasAnAlienSpy: Louis Carrol was apparently a wizard.
** And so is Creator/ChuckNorris.
-->'''Calvin:''' Is that so? Well YOU can kiss MY-- (''timely Rescue'')
* DeathByIrony: One of the Death Eaters who Apparated onto Galaxoid and Nebular's ship is knocked out has his memories modified into him thinking he is a coconut sculptor. He dies in a Death Eater raid two weeks later.
* DistantFinale: [[spoiler:The story ends with Calvin and Susie (And Hobbes and Ursula) married, and sending their children off to Hogwarts.]]
* DoesNotLikeGuns: Ursula, but in that they scare her. To the point that the Boggart the quartet encounter takes on the form of a rifle-wielding hunter when Ursula faces it.
** Calvin ends up becoming an Animagus with a ''Deinonychus'' as an animal form!
** Also, Calvin creates a Wizard Chess set with dinosaurs (and woolly mammoths) as the pieces. These become a ChekhovsGun when Calvin enlarges them to help in the Battle of Hogwarts.
** At one point, Hobbes and Calvin use the Room of Requirement to have Dinosaur Chariot Races. It is ''exactly'' as awesome as that sounds.
* ExpectingSomeoneTaller: This is Hobbes's reaction to seeing Harry for the first time.
* FramingDevice: The entire story is Calvin telling Suzie of his time in Hogwarts.
* HeroicSacrifice: [[spoiler: Natalie jumps in front of Calvin and takes an Avada Kedavra for him]].
* HeroOfAnotherStory: Calvin ends up having several times where his adventures came close to appearing in the canon events of the books (such as [[Literature/HarryPotterAndTheChamberOfSecrets nearly witnessing the Basilisk's first attack, and only narrowly avoiding death]]; [[Literature/HarryPotterAndTheGobletOfFire watching Harry in The Tri-Wizard Tournament, and taunting Percy after it]]; [[Literature/HarryPotterAndTheHalfBloodPrince Calvin catching Draco when he was leaving the Room of Requirement, causing Filch to drag him to Slughorn's party]]; etc), but despite seeing Harry at the Tri-Wizard Tournament, and Ron noticing Calvin's dino form during their year on the run, they don't meet face-to-face until the epilogue, something Calvin lampshades:
-->'''Harry:'''It's really incredible, after all the things we've both done at Hogwarts, that we never once met before now.
-->'''Calvin:''' No kidding. It's almost as if someone wrote this big, elaborate story and then somebody else wrote this other story that coincided with the first story, only it was about different characters and it couldn't disrupt the flow of the first story!
* GoodAngelBadAngel: After Calvin and Susie have a fight in ''In Love and War'', Stupendous Man and the Dictator-for-Life of G.R.O.S.S appear, with Stupendous Man being the angel, and the Dictator-for-Life being the devil, and the whole situation is [[LampshadeHanging lampshaded]] by Calvin. Eventually, a Hobbes and pirate Hobbes appear to assist.
-->'''Calvin:''' "Oh wait a minute, is this one of those shoulder angel bits? Where you're gonna tell to do the right thing and you're gonna tell me to do what I'm gonna do anyway?"
* HeroicLineage: Inverted, somewhat, for Calvin. On his dad's side he's the direct descendant of [[spoiler: the Sorceress Circe and Odysseus, (From ''the Odyssey''),]] and his mother's maiden name is [[spoiler: ''Riddle.'' While it's not confirmed that she's related to ''those'' Riddles, it seems rather unlikely that it's a coincidence, given the crossover.]]
* LanguageBarrier: During Calvin's first class with Snape, Calvin accidentally turns him into Hitler, which also caused Snape to speak German instead of English.
* LaymansTerms: After saving Calvin from the Ministry of Magic, Galaxoid and Nebular tell him that a misty Lepus Europaeus passed though all of htier defences to warn them of Calvin's plight. When Calvin asked what a Lepus Europaeus is, they show him a holographic image of it: A rabbit.
* LeaningOnTheFourthWall: See HeroOfAnotherStory.
* LikeAnOldMarriedCouple: Calvin says this to Galaxoid and Nebular, only to find out that they ''are'' married!
* INeedToIronMyDog: This exchange happens during a conversation between Calvin, a student who wanted to know what the purpose of a rubber duck was, and Ginny Weasley:
-->'''Calvin:''' "Well, y'ever been in the prefects bathroom? The bath they have in there is slightly smaller than the average muggle bathtub."
-->'''Ginny:''' "What were you doing in the prefects bathroom?"
-->'''Calvin:''' "Well, I hope that helps you with your homework. Right now, I have a, um
ice cream in the oven."
-->''Calvin quickly about faced and dashed off around the corner.''
* InvisibleToNormals: Hobbes and Ursula are both a type of magical creature known as a Furry, that's basically a regular animal with human traits such as walking on hind legs. However, muggles see Furries as either regular animals (In Ursula's case) or stuffed toys (In Hobbes').
* NoSell: Hobbes and Ursula, being Furries, are unaffected by any form of magic, including Avada Kedavra.
* OhCrap: In ''In Love and War", upon arriving home, Calvin [[spoiler:destroys the time machine]], but he suddenly realizes that the notes on the Civil War they went back in time in the first place to get were left behind on the Axalon.
* ParanoiaGambit: Calvin pulls one off on Percy. Basically, the prefect made Calvin write out lines saying he wouldn't do various things that he'd done, and he put down a line about putting snakes in Percy's socks. When Percy notices, he acts like it was a mistake, only to reveal to Susie that ''there were no snakes''.
* RaptorAttack: Calvin's ''Deinonychus'' form lacks feathers and is only three feet tall, the same height as a ''Velociraptor''.
* RedemptionEqualsDeath: See Heroic Sacrifice.
* ShoutOut: Several, mostly due to Calvin being Calvin:
** During their time on the run, Calvin put a Undetectable Extention Charm on a rucksack, and specifically tells Hobbes not to compare it to the [[Series/DoctorWho TARDIS]].
*** And again in ''In Love and War'', when Hobbes says that time machines look like blue phone booths.
** When Calvin arranges for a picture to be placed in the Slytherin Common Room, the identity he uses is "Spaceman Spiff of [[Franchise/StargateVerse the Tau'ri]]."
** Calvin and Hobbes sing "[[Music/WeirdAlYankovic Your Horoscope For Today]]" to help their fellow Ravenclaws to chill out.
** "[[WebVideo/AskANinja Thanks for the question, 'Minister'. I look forward to killing you soon! HIYA!!]]"
** Calvin impersonates the [[Franchise/TheMuppets Swedish Chef]] after leaving the kitchens, and had considered using it when teaching the Hogwarts house elves how to cook pizza.
** When Terrasaur kidnaps Susie and Calvin finds out, he rushes to Optimus Primal and shouts ''[[Recap/MyLittlePonyFriendshipIsMagicS1E19ADogAndPonyShow "Optimus! Susie! Tracks, jungle! Disappeared! Terrasaur! Gone, Susie!"]]''
** While Merlin is making a time machine out of Calvin's mother's car, Hobbes replies that the only thing missing is [[Franchise/BackToTheFuture an old man shouting "Great Scott!"]]
** In the "Paranoia Gambit" example above, the format of the joke is ''nearly'' identical to another joke from the comic ''Foxtrot.'' The only difference was that instead of one of the things he's writing lines for being ''fake,'' Jason was writing lines for something ''real'' that he got away with.
** When Ursula gives Hobbes a red handkerchief, Calvin keeps expecting him to say "''They're Gr-r-r-reat!''" like Tony the Tiger.
* ShutUpHannibal: Calvin's speech towards Umbridge during his 'trial':
-->'''Yaxley:''' "We've indulged this one long enough. This court finds the defendant guilty! You will be taken to Azkaban at once."\\
'''Calvin:''' "Guilty of what?! Of existing?! You have no right to do this absolutely no right! You think your precious magic makes you so special, like you're some superior being but you're not! You're just human we're all human, we're all the same, whether people realize it or not and we should all be treated the same regardless of who we are or where we come from or whether we can use magic or not!"
-->'''Yaxley:''' "Hm, amusing! But you see, we ''are'' different! We are wizards. We have power the muggle filth do not have. And that power, by right, makes us superior to the other rabble that populate the world. The muggles are an inferior, insignificant breed. They do not possess the abilities we do. As such, they are no better than the mangy beast of the field."\\
'''Calvin:''' "And you know what the sad truth is? I often wish I was an animal. I've found time and time again that animals have much better qualities than humans. Animals aren't judgmental or critical, they just try and stay out of each others way. And when animals do kill, it's for one of two reasons: either to eat or to keep from being eaten. Animals know nothing of anger, hatred or malice; they only destroy life in order to sustain life."
* TakingTheBullet: [[spoiler: In order to save Calvin's life, Natalie jumps in front of him and gets hit by an Avada Kedavra.]]
* TheLoad: Natalie during Calvin's time on the run. She is too young to use magic and has zero experience camping.
* UnusualEuphemism: Calvin uses ''HOLY SUGAR BOMBS'' as one when he sees the first dragon the contestants in the Tournament had to face.
* WhatTheHellHero: This is Susie's reaction to hearing about Percy basically abandoning his family after Voldemort's revival.
** Calvin is ''very'' unhappy with Galaxoid and Nebular when they reveal they can breathe underwater, since he had ''just'' risked his life saving them because he thought they were drowning! Worse, he risked going to Azkaban, since in order to save them, he used one of the unforgivable curses (granted, it was a) the mind control one, not the torture or insta-kill ones, and b) used on a ''dolphin'', not another human, but it still freaked him out pretty bad) to do it!
* YouDoNotWantToKnow: When Suzie asks what exactly is a horcrux, Calvin and Hobbes both refuse to tell her[[hottip:*: For those who don't know, it's an item that contains a chunk of someone's soul. It's used as a means of gaining immortality, and is considered one of the darkest aspects of magic in the Harry Potter universe]].