->"Plaything? I should say not. It is my egg sac, my ''magnum opus''."\\
"I don't know what a 'magnum opus' is," said Wilbur.\\
"That's Latin," explained Charlotte. "It means 'great work.' This egg sac is my great work the finest thing I have ever made."
-->-- ''Literature/CharlottesWeb''

The term "magnum opus" is Latin for "great work," and is usually used to refer to a work of particularly great ambition, scope, and scale and exceptional quality considered to be the creator's greatest and most renowned work. It is a pinnacle of creative achievement that every artist dreams of reaching and few ever do.

Such a work often represents the culmination of years of painstaking work and toil, and as such, its creation is rife with dramatic possibilities. Characters striving to produce such perfection may fall victim to obsession and neglect their families, social lives, more-lucrative but less-rewarding careers, or even their very health and well-being in their quest. Once their opus is completed, the artist may fall victim to MagnumOpusDissonance if the public doesn't give their work the accolades they feel it deserves.

Even if the work itself is an unmitigated success, the artist may find it a ToughActToFollow; more than one has retired or changed careers after such a momentous undertaking, but finding a new purpose in life after dedicating oneself so fully to such a massive project can prove a challenge in and of itself. On the other hand, in many stories the successful completion of a magnum opus after many trials and tribulations is a HappyEnding and potential CrowningMomentOfHeartwarming.

For examples of what creators believe to be their greatest work, see CreatorsFavoriteEpisode.

!!InUniverseExamplesOnly:

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[[folder:Anime and Manga]]
* In ''Manga/{{Berserk}}'', Griffith describes a dream as something that a man spends his whole life working on, whether it be world domination or the perfect tempering of one sword. The last one perfectly describes Godo, the old master weapon smith who ultimately arms Guts with his armor and the BFS called the Dragon Slayer. The creation of the Dragon Slayer certainly qualifies; as Godo told Rickert, he was a young man working for kings and nobles and had grown tired of making refined and elegant weapons. When the king announced a contest to create a sword that could slay a dragon, Godo created a monstrous tool too big to be called a sword, because he wanted to make a point that to kill an impossible creature you would need an equally impossible weapon. That insolence forced him to leave court and set up shop in the middle of nowhere, but he kept that slab of iron as a reminder of when he bit off more than he could chew. Years later, Guts comes to him and needs a weapon. Godo gives him a finely made sword sharp enough to cut another sword in half, but when a demon appears Guts finds that a sword made to kill humans is too fragile for the job. Instead he takes up the Dragon Slayer and butchers the creature, and it has been his trademark weapon ever since. Godo ultimately acknowledged that the Dragon Slayer was his greatest creation, and the last act of forging he ever did was to repair it so that Guts could go and rescue Casca from the Tower of Conviction.
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[[folder:Film]]
* In ''Film/BartonFink'', the title character believes he has created his greatest work when he writes a screenplay for a wrestling film starring Wallace Beery that is full of the same themes of social consciousness he has tried to address in his stage plays. Unfortunately, his studio bosses wanted him to write a StrictlyFormula wrestling film, and his screenplay gets his supervisor fired and Fink himself locked into a contract in which he is promised that none of his scripts will be produced.
* In ''Film/TheImitationGame'', Alan Turing considers his cryptography computer to be his life's work and obsesses over it constantly.
* In ''Film/KillBill'', the swordsmith Hattori Hanzo used to make the most perfect and deadly Japanese swords in the world, but gave up his craft because he didn't want to be responsible for any more death. However, the Bride tracks him down in Okinawa and convinces him to break his vow and make one last sword for her. He spends a month on this deeply spiritual task, and presents it to her as his last and greatest masterpiece.
-->''"I can tell you with no ego this is my finest sword. If on your journey, should you encounter God, God will be cut."''
* ''Film/MrHollandsOpus'' tells the story of Glenn Holland, a composer and high school music teacher who struggles to meet the competing demands of his family, his teaching career, and the creation of a symphony that he considers his life's work. By the time he completes his symphony, it appears he will be unable to find the financial backing to ever hear it performed. [[spoiler: In the end, many of his former students and colleagues secretly gather on the day of his forced retirement from teaching and surprise him by performing his symphony for him. The question of whether the "Mr. Holland's opus" of the title refers to the symphony itself or the sum of all the lives he has touched over his career is left as an exercise for the viewer.]]
* In ''Film/WalkHard'', Dewey Cox spends much of his musical career and, indeed, much of his life working on his magnum opus "Beautiful Ride," a song that encompasses an entire lifetime of ups and downs and which is so grand in scope that at various points in its creation it requires a veritable army of singers, musicians, and [[UpToEleven barnyard animals]] to perform it. Indeed, it is ''such'' a crowning achievement in Cox's life that, after its first and only live performance, [[ParodiedTrope he drops dead, his life's work complete]].'
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[[folder:Literature]]
* In ''Literature/CharlottesWeb'', Charlotte the spider describes her egg sac as her magnum opus, the finest thing she has ever made. Or, as it turns out, ''will'' ever make, as [[spoiler: she dies, as spiders do, shortly after producing it.]]
* In ''Literature/ASongOfIceAndFire'', there is a legend about a swordsmith who worked day and night trying to create the perfect sword, but always failed at the last stage. He finally succeeded by stabbing it into his own beloved wife, causing her blood to temper the blade and make it unsurpassed at killing.
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[[folder:Live-Action TV]]
* In the ''Series/{{Blackadder}} the Third'' episode "Ink and Incapability," Blackadder spends seven years writing ''Edmund: A Butler's Tale'', "a giant rollercoaster of a novel in four hundred sizzling chapters, a searing indictment of domestic servitude in the eighteenth century, with some hot gypsies thrown in," and describes it as his magnum opus. (Followed immediately by a parody in which Baldrick produces his [[{{Malaproper}} "magnificent octopus"]], which, as he doesn't like long books, reads simply, "Once upon a time, there was a lovely little sausage called Baldrick, and he lived happily ever after.") And Samuel Johnson agrees that Blackadder's book is a masterpiece, pronouncing it the only book superior to his dictionary. A pity he's the only person besides Blackadder who ever gets to read it before a misunderstanding leads Baldrick to throw it on the fire...
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[[folder:Theatre]]
* In ''Theatre/{{Amadeus}}'', Salieri's plot to surpass and destroy Mozart involves commissioning Mozart to write the greatest work of his life, killing him, and then presenting it as his own work. This work turns out to be the ''Requiem Mass in d minor'', and the strain of composing it is what ultimately [[spoiler:causes Mozart to die of exhaustion]].
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[[folder:Western Animation]]
* In the ''WesternAnimation/RockosModernLife'' episode "Wacky Delly", successful animator Ralph Bighead wants to get out of the animation business to make "real art", and HilarityEnsues. The episode ends in a FlashForward showing Ralph after he has complete his life's master work, a still life of wine and fruit carved into a mountain ''a la'' Mount Rushmore. The subtitles tell the viewer that its creation has taken ten years, although judging from Ralph's mop of white hair and long white beard, those years have taken a toll on him. Nevertheless, he is ecstatic to see his life's work completed... until a passing hillbilly says that it's not bad, but also not as good as ''[[ShowWithinAShow Wacky Delly]]'', the show that Ralph had spent the episode up until that point [[MagnumOpusDissonance attempting to make as bad as possible]] in an attempt to get fired from his animation contract.
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