What Stephen King book is The Monkey based on? Short story & movie differences explained

Osgood Perkins’ adaptation of The Monkey is finally out, and Stephen King fans might have noticed a few changes made from the original book.

2025 is shaping up to be a killer year for Stephen King movies. The Running Man is also coming out, and The Long Walk has wrapped production, with a release date to be confirmed.

But none of these are as exciting as The Monkey, headed by the mastermind behind Longlegs, Osgood Perkins.

The Monkey may be one of King’s more unknown stories, but with intense violence and a freaky killing toy, it’s one you ought to know. Here’s a breakdown of what the book is actually about, and what changes the horror movie made. (Warning: major spoilers ahead!)

What book is The Monkey based on?

The Monkey is based on Stephen King’s short story of the same name, ‘The Monkey’, which was published in 1980.

The story was first published in Gallery magazine, and was later revised and published again in King’s Skeleton Crew collection in 1985.

The basis of the short story is the same for Osgood Perkins‘ movie: It’s a monkey toy that kills people – simple as that.

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In King’s story, Hal Shelburn (played by Theo James in the adaptation) is in possession of a killer toy monkey that brings death to everyone around him. Hal’s son, Dennis, finds the monkey in the attic of Hal’s childhood home.

The rediscovery of the toy causes Hal to relive his childhood, when he first found the monkey in his own father’s possessions. As Hal grew up, he noticed that every time the monkey clapped the cymbals, someone would die in a horrific way.

To rid himself of the cursed object, Hal threw it down a well. However, the monkey returns decades later, causing Hal to fear that his family might be next. Together, he and Dennis head out to Crystal Lake, where Hal rows out on a boat and attempts to drown the monkey in the water.

However, he still hears the monkey clapping its cymbals. Hal just about manages to escape as his boat sinks, but the story later ends with a newspaper clipping that says all the fish in the lake suddenly died.

What changes does the movie make?

There’s quite a few differences in Osgood Perkins’ adaptation of the monkey, starting with the fact that Hal is actually a twin in the movie version.

Hal and Bill are twin brothers

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Most notably, Hal is an only child in the short story. However, in the movie, Theo James plays both Hal and Bill, twin brothers who couldn’t be more different.

Hal is timid and plays second fiddle to his older, ruder brother Bill, and even fantasizes about killing him. As adults, the pair don’t speak, except for when Bill calls up Hal and tells him “the monkey that likes killing our family” is back.

Later, it’s revealed that Bill has a deeply unhealthy relationship with the monkey and has been searching for it decades after they dropped it down the well together. He worships the monkey and wants to harness its power to kill Hal, believing he is to blame for their mother’s death.

Hal has a very different son

The short story kicks off with Hal’s son Dennis discovering the monkey in the attic. However, in the movie, Hal is a distant father and only sees his son (renamed Petey) once a year for his own protection. Petey only gets involved because Hal is taking him on one last road trip.

All in all, their relationship is far more strained and awkward than the book. But despite this, they still have to work together at the end, with Hal needing to stand up to Bill in order to save Petey from his clutches.

A much deadlier ending

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While the original short story’s ending has a far more “Homer electrocuting the river of fish” vibe, The Monkey’s movie version takes a different route.

Bill has tricked Petey and Hal into turning up to his warehouse hideout where he’s been keeping the monkey. He wants Petey to turn the key in the hopes that it’ll kill Hal, but when he gets frustrated and tries to force the monkey to beat its drum (more on that later), the monkey goes berserk and starts killing everyone in the town.

Planes crash, fires break out, and hundreds of civilians die in horrible, messy ways. That includes Bill, who gets a swift bowling ball to the head after he and Hal finally make up after all those years. Finally, Hal and Petey get in their car and drive home, passing by all the death and destruction on the way.

The monkey has a different design from the book

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Let’s address the monkey in the room: in Stephen King’s book, the titular primate has cymbals instead of a drum. When he chimes his death toll, it’s in a completely different manner. The cymbal version is the far more recognizable and classic version of this particular toy, and one featured in the art for the short story.

However, there’s a good reason for this: Disney owns the copyright on the cymbal monkey design. Because that design was used in Toy Story 3, Perkins was told he had to work around it.

“When I was given the assignment, the producer said, ‘Oh, by the way, Disney owns the cymbals, because of [the toy monkey in] Toy Story,'” he said [via Games Radar]. “So it [couldn’t] be cymbals. What if it was a drum? It’s one of those things where a limitation becomes an opportunity.

“If you’re making movies and you’re not up for that adage then you’re in real trouble! ‘I was like, ‘Hey, that’s awesome. The drum is better.’ The drum is like a marching drum. It’s like, ‘Drum roll, please!’ before something happens. That’s better than cymbals. So thanks, Disney. I prefer it!”

Thankfully, the movie monkey is just as freaky-looking, with wide reddish eyes. His hammering on the drum is also more intense, since he has to raise his arm in the first place, teasing each and every kill with intent. And, of course, he has a cool little drumstick twist move.

The Monkey is playing in theaters now.

For more, check out all the other best-looking horror movies coming out this year. You can also check out the most violent horror movies ever made, and find out what new movies are coming to streaming this month.