The Shelburn Family
Hal
Hal Shelburn
Played By: Theo James, Christian Convery (young)
The main protagonist of the film, a socially awkward, troubled divorcee estranged from his family.
- Always Identical Twins: The twins are completely identical save for Hal wearing glasses to distinguish himself from his brother.
- Cain and Abel: Hal and Bill never really had a good relationship; Bill was a horribly cruel Big Brother Bully to Hal, to the point that Hal fantasized about killing him, and, using the monkey, eventually tried to, resulting in the accidental death of their mother. As adults, they unsurprisingly fell out of touch, with Hal even telling Petey that he doesn't have any siblings. It's eventually revealed that once he got his hands on the monkey again, Bill starting using it regularly to try and kill Hal out of a myopic notion of revenge, leading to most of the deaths in the movie. He even goes so far as to force Petey to use the monkey, hoping that he'll accidentally kill his father the same way Hal accidentally killed their mother.
- Cruel to Be Kind: Hal as an adult minimizes contact with the remainder of his family to the extent that he can, and they resent him for it. However, they don't understand that he's trying to protect them from the Monkey.
- Daddy Had a Good Reason for Abandoning You: Hal only sees Petey about once a year because he fears the monkey will come back and kill his family members, including Petey, so he distances himself so they won't get harmed.
- Disappeared Dad: In the present day, Hal is this to Petey, only seeing him once per year on his own request, to the point where his ex-wife’s new husband is on the verge of legally adopting Petey. Though this is more a case of Daddy Had a Good Reason for Abandoning You given his fear that the monkey would return and kill yet another family member, which could potentially mean his son. By the end of the film, Hal seems to be on his way to subverting this trope once and for all after accepting the monkey’s role in the family’s life.
- Foolish Sibling, Responsible Sibling: Neither sibling is free of issues. But Hal at least holds down a steady job, even if it's a lower-paying one that makes the rest of his family think of him as a loser. And he also minimizes contact with his family with the selfless intention of protecting them from the evil power of the Monkey. Bill on the other hand takes possession of the Monkey with the intention of killing Hal out of revenge for their mother, and doesn't care that dozens of innocent people who had nothing to do with what happened in the past are dying because of it.
- Rage Breaking Point: While Hal could mostly endure just Bill bullying him, once Bill got a group of girls to start doing it too, to the point of publicly humiliating him for fun, Hal snapped and tried to use the monkey to kill Bill.
- Screw This, I'm Outta Here!: Hal's understandable tendency is to pack up and leave whenever he witnesses yet another death caused by the Monkey. He wakes up Petey to leave the motel after the bikini-clad woman exploded into Ludicrous Gibs. He also wants to leave town after the shotgun blast likewise blew apart the realtor, except that the police won't let him. It gradually becomes subverted when he accepts that it falls on him to somehow seal the Monkey away.
- Socially Awkward Hero: While already shy as a child, as an adult, Hal is incredibly socially awkward. He struggles to communicate meaningfully, is extremely stoic and reserved, and often stumbles over his sentences.
- Suddenly Shouting: After witnessing one of the monkey's freak accidents cause a woman to explode, Hal wakes Petey up telling him they need to leave. He starts out as impressively soft-spoken given the circumstances, but when Petey is understandably confused...
Hal: WE NEED TO MAKE! LIKE! EGGS AND SCRAMBLE!
- Unfazed Everyman: After the Time Skip, Hal has been so Conditioned to Accept Horror he's become this. He's an awkward, but ordinary blue-collar worker who reacts to the horrific deaths the monkey causes with bumbling gruffness. He only loses his cool a few times, after particularly absurd and/or dangerous events.
Petey Jr.
Petey Shelburn Jr.
Played By: Colin O'Brien
Hal's estranged son who wants to reconnect with him.
- Calling Parents by Their Name: Petey calls his father Hal by his name.
- Emo Teen: Justified. Petey is perpetually sullen and gloomy, and at times abrasive. However, a lot of it stems from his dysfunctional family and the fact he's on a road trip with a father who rejects every attempt he makes to reach out.
Bill
Bill Shelburn
Played By: Theo James, Christian Convery (young)
Hal's abusive twin brother.
- Always Identical Twins: The twins are completely identical save for Hal wearing glasses to distinguish himself from his brother.
- Asshole Victim: Bill gets his head blown off with a bowling ball. Even though he did attempt a Heel–Face Turn, he was still an unpleasant jerk who was using The Monkey to try to kill his brother Hal and instead killed half the town. Petey even brings up how, sure, everyone dies, but he was absolutely deranged.
- Big Bad: Bill becomes this by the present day part of the movie. While the Monkey is a devious instrument of death, it still needs someone to actually activate it. And after discovering how Hal accidentally killed their mother with the Monkey when he intended to kill him instead (an action driven by his constant bullying of his brother), Bill becomes dead set on getting revenge on Hal by killing him with the Monkey, no matter how many attempts it takes.
- Big Brother Bully: Bill towards Hal in spades. Feels entitled to it as well on the basis of having been born a few minutes earlier than his identical twin and having eaten his mother's placenta. He even encourages the girls at school to torment his own brother whenever possible.
- Cain and Abel: Hal and Bill never really had a good relationship; Bill was a horribly cruel Big Brother Bully to Hal, to the point that Hal fantasized about killing him, and, using the monkey, eventually tried to, resulting in the accidental death of their mother. As adults, they unsurprisingly fell out of touch, with Hal even telling Petey that he doesn't have any siblings. It's eventually revealed that once he got his hands on the monkey again, Bill starting using it regularly to try and kill Hal out of a myopic notion of revenge, leading to most of the deaths in the movie. He even goes so far as to force Petey to use the monkey, hoping that he'll accidentally kill his father the same way Hal accidentally killed their mother.
- Complexity Addiction: Bill goes to elaborate lengths to retrieve the monkey and use it to try and kill Hal, as well as setting up various death traps in his base, when if he wanted Hal dead he could just go off and try and kill his brother himself. At the very least, it's clear that his focus on successfully utilizing the Monkey to cause Hal's death is a twisted form of Karmic Death for Hal accidentally causing the traumatic death of their mother when trying to use the monkey on him, completely disregarding both how Bill drove Hal to that through his abusive bullying and Hal's action was, at worse, an impulsive mistake made by a child that he regretted for the rest of his life.
- Didn't Think This Through: Despite knowing that the monkey kills at random and having figured out that it "misfired" when Hal tried to use it on him when they were children, Bill goes through at least a dozen innocent people before figuring out what Hal realized after one attempt: the monkey "doesn't take requests". Even his plan to make Petey unknowingly turn the key suffers from this flaw, since for all Bill knew, it was just as likely to kill a total stranger (or even Bill himself) as Hal.
- Even Bad Men Love Their Mamas: Bill’s Start of Darkness began with the death of his mother Lois, for which he never recovered from emotionally. He blames Hal for Lois’ death (though it was completely unintentional on Hal’s part), and his primary purpose in life seems to be destroying his brother in revenge for Lois’ death.
- Even Evil Has Standards: Bill, while not exactly evil at that point, insists to Hal that they should throw the monkey in a well to keep genuinely evil people (like Nazis or "Iranqis") from using it. He's not exactly being honest; as soon as he gets the chance to go back for the monkey on his own, Bill does, hoping to use it to kill Hal for their mother's death.
- Foolish Sibling, Responsible Sibling: Neither sibling is free of issues. But Hal at least holds down a steady job, even if it's a lower-paying one that makes the rest of his family think of him as a loser. And he also minimizes contact with his family with the selfless intention of protecting them from the evil power of the Monkey. Bill on the other hand takes possession of the Monkey with the intention of killing Hal out of revenge for their mother, and doesn't care that dozens of innocent people who had nothing to do with what happened in the past are dying because of it.
- Heel–Face Door-Slam: Bill seems to finally learn his lesson and wants to truly try to connect with Hal and try to be a better person. Just as this happens, he immediately gets his head blown off.
- It's All About Me: Bill clearly only cares about his own feelings and never once considers someone else's, such as being upset at his babysitter's death because he had a crush on her. In the present, he only cares about getting revenge on Hal for accidentally killing his mother, not caring that she was Hal's mother too. By his own admission, he never even considered the fact until Hal pointed it out.
- Kids Are Cruel: Bill was a relentless bully to Hal in their youth, and after he got a group of girls in on the "fun" of bullying his brother, they kept at it until the brothers moved away.
- No Sympathy: Bill is apathetic to Uncle Chip's death or the fact he caused it by activating the monkey because he was "kind of an asshole". He only decides to get rid of the monkey because he was worried it would kill someone he actually cares about.
- Psychopathic Manchild: Bill is developmentally stuck at the moment of his mother's death. He spent 25 years obsessing over finding the Monkey to use it on Hal once he realized Hal was the one who used the Monkey when it killed their mom. He tailored his childhood funeral suit so he could wear it, but it's still much too small for his frame and added a flame patterned cummerbund. He used the Monkey over and over trying to kill Hal not caring about the innocent people killed by the "misfires." He only refers to Lois as his mother and honestly never considered Hal would be as tortured by her death as he was until Hal points out she was his mother too.
- Schoolyard Bully All Grown Up: Bill, even leaving aside outright trying to kill his own brother, is still every bit this towards Hal. He even does his hand in the hair instead of shaking on a deal thing, twice. Hal can't help but roll his eyes in the realization that Bill hasn't truly grown up.
Lois
Lois Shelburn
Played By: Tatiana Maslany
Hal and Bill's sarcastic, bitter but loving mother.
- Blood from Every Orifice: Lois dies from a sudden brain aneurysm that causes blood to gush from her eyes and mouth as she struggles to gasp for air before collapsing to the ground. Hal later has a nightmare where Lois leans over him while giving him "life advice" to "try not to kill everyone around [him]" as blood begins to pour from her eyes, ears, and mouth again before she screams into the camera.
- Brutal Honesty: Lois never sugarcoats the harsh truth from her children. After their babysitter's death, Lois explains to Bill and Hal how everyone dies some day, then goes on to explain how some will die peacefully in their own beds while others will die in agony, screaming through tape gags.
- Parents as People: Lois is pretty openly bitter about being a single mother, but genuinely loves and is supportive of her sons. However, she also never really makes an effort to stop Bill's abuse of Hal, which leads to their relationship deteriorating even further after Lois dies.
Uncle Chip
Chip Zimmer
Played By: Oz Perkins
Hal and Bill's swinger uncle.
- Asshole Victim: Bill has no sympathy for Chip's death at the monkey's hand because he was "kind of an asshole."
- Brutal Honesty: Uncle Chip explains to Hal that he and his wife never wanted kids or any real responsibility and that they're swingers. He promises that they're going to do their very best but admits that might not be very good.
- Disco Dan: Uncle Chip and Aunt Ida dress and act as though it is still the 70s, despite the first part of the film taking place in 1999. Even in 2024, Ida still has her 70s shades.
- Ludicrous Gibs: Uncle Chip bites it when a herd of stampeding wild horses trampled over his sleeping bag during a hunting trip. When the coroners unzipped the bag to examined his body, there's none left as it's reduced to bloody, chunky mince meat. They specifically say that it left him looking like "somebody drop-kicked a cherry pie".
Aunt Ida
Ida Zimmer
Played By: Sarah Levy
Hal and Bill's swinger aunt.
- Disco Dan: Uncle Chip and Aunt Ida dress and act as though it is still the 70s, despite the first part of the film taking place in 1999. Even in 2024, Ida still has her 70s shades.
- Too Dumb to Live: Aunt Ida notices an odd smell and a mysterious hissing noise coming from one of her gas-powered stove's burners. Her response is to lean in close and put her face right over the burner, after covering her entire face with rubbing alcohol for unrelated injuries. You can guess what happens next, and even though this doesn't kill her directly, it is the directly contributing cause to what does.
Petey Sr.
Peter Shelburn Sr.
Played By: Adam Scott
Hal and Bill's absentee father.
- Everyone Calls Him "Barkeep": He's always referred to as "your father" by anyone besides the twins, and his real name is only mentioned once.
- Hero of Another Story: The prologue establishes Petey Sr. had his own horrific misadventures with the monkey that we only get to see a portion of.
- Noodle Incident: Petey Sr. quite evidently had his own gruesome ordeal with the monkey just before the events of the movie, as he is covered in someone else's blood when he attempts to return the monkey to the antique shop during the prologue. What that entailed will forever remain a mystery.
- Uncertain Doom: The fate of Bill and Hal's father remains a mystery. He is last seen in London attempting to destroy the monkey with a flamethrower, and his family never saw him again. Whether he simply cut all ties with his family in an attempt to protect them from the monkey (like Hal did with Petey) or the monkey killed him as revenge for burning him (similarly to what he did to Bill), is impossible to say - although Hal did chop it up as a child, and the Monkey spared both him and Petey, so maybe it doesn't take attempts to destroy it personally, after all it recovered from both attempts.
Others
Ricky
Ricky
Played By: Rohan Campbell
A dimwitted, thuggish local thrasher.
- Alas, Poor Villain: His father was a deadbeat who left him, his mother, and brother for a stripper leaving his sons and wife.
- Tragic Villain: like above his father left him when he was a child.
- Hiding Behind Your Bangs: Ricky’s eyes are almost never seen under his bangs.
- Juggling Loaded Guns: Ricky, in his infinite stupidity, tries to scratch his head with a loaded gun that unsurprisingly fires off a bullet in the car. This plays in to his death, no less.
Dwight
Dwight
Played By:
Hal's easygoing boss.
- Brutal Honesty: When Hal tells him he has a son, Dwight is honestly surprised. When Hal confirms it, Dwight sympathetically says his Character Catchphrase, "That sucks."
- Character Catchphrase: "That sucks."
- Major Injury Underreaction: When the monkey causes him to choke to death on his vape pen, Dwight simply lets out one final, deadpan: "That sucks."
Rookie Priest
Rookie Priest
Played By: Nicco Del Rio
A bumbling priest.
- The Ditz: He seems woefully out of his depth, going on meandering tangents at the pulpit, and clumsily condenses the idea of any Divine Plan down to essentially a celestial coin flip.
The Monkey
The Monkey
The titular antagonist, it is a mysterious, supernatural entity that orchestrates freak accidents.
- Berserk Button: It turns out that the Monkey hates it when someone tries to force it to kill a specific target; Bill finds out the hard way when he demands it to kill Hal and tries to force its drumstick down to no avail — only for the Monkey to suddenly sport a very pissed off look on its face towards Bill as it proceeds to play it's drum with uncontrollable speed as it causes widespread death and destruction throughout the entire town while still sparing Hal.
- Evil Is Not a Toy: Played both literally and figuratively.
- All throughout the movie various Shelburn men keep having to tell people that the monkey is very much not the toy it appears to be.
- Both brothers learn the hard way that the monkey absolutely cannot be used as a weapon against one’s enemies, because the thing has a mind of its own and it will kill whomever it wants to kill. Specifically, both times the Monkey is triggered in hopes of targeting a specific person, it will instead aim for anybody else who'd be viable, or even random strangers if it'd avoid doing its "owner's" bidding. When Hal triggers it in hopes of affecting Bill for his bullying of him, it instead kills their mother, traumatising them both. Bill later finding this out and trying to use the Monkey to "return the favour" instead has it affecting anyone but Hal, up to and including causing a death spree throughout the town in the climax that still spares Hal. And once both brothers finally bury the hatchet over their shared grief for their mother's passing, the Monkey then kills Bill with one of his own booby traps, evidently as punishment for his hubris in trying to control it.
- Ricky, once he learns what the Monkey does, covets it precisely because he thinks it would be a cool new toy to play with, that ending other peoples' lives would be a game to him. He gets eaten alive by the wasps for his troubles.
- Nothing Is Scarier:
- Like the short story, it's never explained where exactly the Monkey came from or why it has the power to cause sudden death.
- The monkey's drum playing is normally accompanied by Creepy Circus Music. After Bill tries and fails to force it to kill Hal, its subsequent drumroll to kill off a huge chunk of the town is done in complete silence.
- While chopping up the monkey in an attempt to destroy it, young Hal discovers its insides are fleshy. This is never explained.
- Restraining Bolt: The Monkey's key is this. Whilst it can cause inescapable death to those around the user by banging its toy drum, it still requires somebody to willingly turn the key first to trigger its mechanisms, and otherwise is just an ordinary, if indestructible, toy monkey. This puts the villainous actions of the film's latter half squarely on Bill's head, in his insane attempts to kill Hal with the Monkey despite causing numerous "misfires" from the evil toy's refusal to obey his wishes. When he reaches the apex of his Villainous Breakdown in the climax, he tries to force the Monkey to bang the drum without turning the key...and the Monkey then starts rapid-fire drumming without stopping, causing mass death to erupt across the town. By the end, Hal and Petey agree to accept their fate as the Monkey's "owners", preventing anyone else from turning the key on the toy for the rest of their lives, as the only method they have of neutering its power.