"I don't think I'm ready to be a grown-up."
Sometimes people just fail to develop into social or intellectual maturity. Maybe it's due to a very loving but confining mother or father. Or maybe they just didn't want to leave the nest. Maybe they've been intentionally secluded from learning about the world. Maybe it's the result of brain damage or something more sinister. Perhaps they just never had a life-changing moment involving a shotgun and a beloved pet. Maybe it's just a form of Mars and Venus Gender Contrast. Who can say?
Although the causes might not be clear, the effects are. The Man Child, a term invented by William Faulkner, is usually an adult who possesses a very childlike or childish demeanor. He's emotionally both simple and fragile; he prefers (although does not always need) to have a parent figure to look after him. He usually isn't very worldly and is typically pretty gullible. The Man Child's interests are usually what most people consider to be immature or childish, even in comparison to actual children.
In the vast majority of cases, the character is Always Male. This is (presumably) to contrast the differences between him and "normal men" with the normal responsibilities and wisdom of adulthood. The female version is usually split between The Ingenue, the Genki Girl, or other tropes which highlight an adult woman's child-like attributes rather than her grown-up persona. "Man Child" has many more negative connotations than The Ingenue; the Man Child's immaturity and lack of outward adult behavior is emphasized as being a bad thing versus being an emphasized good thing like The Ingenue's purity and idealism. On the Brain Chain, the Man Child occupies a space between The Cloudcuckoolander and The Ditz, but without necessarily becoming The Fool. He usually does not have The Fool's luck, but he doesn't necessarily play the role of the Butt Monkey either. Although the Man Child is commonly portrayed as being mentally challenged he does not necessarily have to be.
In comedic works, he usually plays the role of The Ditz. In dramatic works, he could be the Jerk with a Heart of Gold due to his simplicity or immaturity, or he could be the sympathetic character we come to love. Sometimes the Man Child embarks on a late-in-the-day Coming of Age Story, which ushers him into true adulthood. Note that usually Sex as Rite-of-Passage works only some of the time for this. In many instances, A Man Child is not a virgin, but only sees sex as a tool of pleasure and does not recognize its emotional significance.
One of the Kids is related, in where their childishness is caused by spending a lot of time around children.
Does not relate to Never Grew Up, because they physically did grow up - but never outgrew being attached to immature or childish things or behavior. Sister Trope (perhaps) to Adults Dressed as Children, although that trope is almost always played for laughs or borders on the grotesque. Compare Keet, One of the Kids, Kiddie Kid. For a villainous version, see Psychopathic Manchild. Not related to Manchild, the British TV series, either.
For similar tropes or works named Man Child, Manchild, or Man-Child, see the disambiguation page at Manchild.
Anime and Manga
- Apachai Hopachai in Kenichi: The Mightiest Disciple is known as the "Death God of the Muay Thai Underground" and is a deadly fighter in combat. Outside combat, however, he's very innocent, gentle, and childlike.
- Doctor Tokita in Paprika.
- L from Death Note. He sits like a kid, eats a lot of sugar, playing with his food, and in the anime, after hearing something important, ran and dove head first on the couch like a ten year old boy would.
- They give the reason for his sitting position being that the brain gets the most oxygen from that posture. His liking of sugary foods has been explained is special material as being necessary for his brain, which burns calories like mad.
- Near is a classic example of this trope and even more-so than L. He's 17-18 in the post-timeskip(21 in the post-series one shot) and he's always seen playing with toys.
- Milla Ackerman from Godannar before regaining her full memories.
- Galactic otaku Keroro Gunsou is this - followed Pekopon anime as a child, then subjected to Training from Hell until he was assigned to Pekopon to lead the invasion... making it far easier to follow his old hobbies as a result. Just picking up where he left off in life.
- Figure skater Azusa Shiratori from Ranma ½ is a spoiled 16 year old girl who acts like a 5 year old, she'll steal anything she considers cute even if it's just a food item and she will give it a pet name, if the person who has the thing she wants won't hand it over she will attack them with anything she can find.
- Played for Drama in Kodomo no Jikan. Reiji is able to support Rin and himself financially as an office worker but he is incredibly messed up due to his abusive childhood and the death of his lover/cousin Aki, Rin's mother. He has severe dependency issues as a result and sees nothing wrong with trying to raise Rin to take Aki's place. He even mentally regresses to a child when he thinks Rin might abandon him.
- Usagi from Junjou Romantica appears to be this. He's actually trying to simulate a child's environment because he wanted to "recreate what normal kids do in their childhood".
- Axis Powers Hetalia; yes, new viewers, the character throwing a tantrum and beating a dragon with a Hello Kitty doll is a four-thousand-year-old man.
- Nemi is a rare female example.
- Asterix's sidekick, Obelix.
- Brewster Rockit, from Brewster Rockit: Space Guy!, is shown to be a manchild, even having book tapes on coloring books of all things, and being exceedingly stupid. It is implied that he originally had average human intelligence, but his intelligence and maturity decreased substantially due to the government overdosing him on memory wipes.
- Madman, due mostly to being killed and reanimated with new memories and a different personality. Mentally, he is only about ten years old (at least when his former life isn't poking through).
- In Empire State, Jimmy admits that he really doesn't feel grown-up, even though he's 25. But when his friend Sara calls him out for not having a checking account, and still receiving an allowance from his mother, he insists that "it's an Asian thing".
- Captain Marvel often comes across this way, but for a different reason—he's literally a young boy (or sometimes teenager) named Billy who can transform into an adult superhero. Early on the two forms had different personalities, but most modern interpretations make them the same person, acting like a Cheerful Child in both forms (though Marvel gets a bit of maturity from having the Wisdom of Solomon as one of his powers).
- Similarly, Rage of Marvel's New Warriors was an immature young teen when he got his powers—which mutated him into the form of a very large and muscular Scary Black Man.
- Pretty much any character played by Zach Galifanakis, notably in The Hangover and Due Date.
- Sam from I Am Sam, although he actually is mentally retarded.
- In The Wrestler, the main character is one, and it's shown in a tragic, negative light.
- Chance the Gardener in Being There; in the movie version his maid Louise actually says "You're always gonna be a little boy, ain't cha?" when she leaves after the death of the master of the house. It's stated in the book and heavily implied in the film that he is mentally challenged; the twist is that most of the other characters don't recognize this, making the character a Trope Namer for similar mistaken identity situations. Peter Sellers played him in the film; he initiated its making because he identified with the character so strongly when he read the book. For better and worse, he was a Real Life example of this.
- Pee-wee Herman takes this to the extreme, particularly in Pee-wee's Big Adventure where for the most part, the rest of the world accommodates his strange ways without question. He is apparently a homeowner with lots of friends. He even has a rival Man Child in Francis, an adult spoiled brat who only has slightly more street smarts.
- Pee-wee's also had several love-interests (namely Dottie from "Big Adventure," Miss Yvonne on "Pee-wee's Playhouse," and Winnie and Gina from "Big Top Pee-wee"). And they're all pretty good-looking. However the heck he managed to pull that off...well, the world may never know.
- Adam Sandler's entire career is built on this trope, most notably Billy Madison.
- In another Burton flick, Charlie and the Chocolate Factory, is Willy Wonka, a character eerily similar to Pee-Wee Herman. But, while Wonka appears to be completely unselfconscious of what a Man Child he is, (at one point in the film, he argues that he was never as small as a child, because he remembers being able to reach his head to put a hat on top of it) unlike Herman's world, Wonka's notices and is more than a little squicked by him.
- Played with in The 40 Year Old Virgin; the main character is, as the title suggests, not sexually active, and also dresses in a rather buttoned-down fashion, has a typically childish hobby of collecting comic-book action-figures and is slightly naive and inexperienced, coming across on the surface as being one of these. However, on the whole he's actually managed to get his shit together a lot more successfully than many of the supposedly more 'experienced' men and women around him, and generally comes off as being a lot more mature, well-rounded and wise about life than them.
- The male lead in Knocked Up also has many Man Child traits.
- Buddy from Elf is over 35 years old and still acts like a six year old and has a very infantile view of the world; this is due to being raised by elves from infanthood.
- Step Brothers take this trope and turns it up to eleven.
- The main characters of the film Mystery Team are a group of "Kid Detectives" who still continue their exploits even though they're in their late teens and still having the mental age of seven. They are hired by a girl to solve her father's murder.
- In Finding Neverland, James Barrie is (mostly) capable of taking care of himself, but he has an air of immaturity and childlike wonder about him, and he clearly has much more fun playing make believe with the Llewelyn Davies boys than he does socializing with adults.
- Justin from Kickin It Old Skool, this is justified as he was in a coma for 20 years.
- Sam Flynn in Tron: Legacy acts more like a rebellious teenager seeking thrills than the 27 year old that he is. At the end of the movie, he decides to start working at Encom.
- His dad was once just as bad. When we first see him, he's holding court at the arcade machines, showing off his insane-level skills at playing them. His apartment/office overlooks said arcade. Lora (his ex) shouts in frustration "Now, you see why all his friends are fourteen years old!"
- Both John and Dean Solomon from The Brothers Solomon.
- Any character played by Harpo Marx.
- The Hot Chick.
- In the American version of Fever Pitch Jimmy Fallon's character is called a manchild by his girlfriend, but all-consuming passion for the Red Sox aside he's a comparatively mild example: he's good with women, has a job as a well-respected junior high math teacher, and he has his own apartment.
- Billy from Buffalo '66 is gradually revealed to be this. He doesn't like girls, he makes up bizarre stories, he bullies his friend, and is naive enough to get in trouble with gamblers.
- When the two of them aren't killing gangsters, Connor and Murphy McManus, The Boondock Saints, are prone to bickering and tussling like ten-year-old boys.
- This troper's surprised that nobody's mentioned Captain Jack Sparrow.
Jack: I GOT A JAR O' DIIIIIRT, I GOT A JAR O' DIIIIIRT, AND GUESS WHAT'S INSIIIIIDE IIIIIT?
- Charlie from Flowers for Algernon is phenylketonuric man in his forties who remains very childish, naive and idealistic. He had also never had wet dreams or been attracted to women at the beginning of the book, although the realism of this aspect of his disorder is somewhat doubtful.
- Tom Cullen in The Stand (due to being mentally disabled).
- Dorian Gray, from The Picture of Dorian Gray seems like one of these when first introduced. His innocence is obvious, and he is naive and gullible enough to be influenced by his friends to adopt their lifestyle right away, without any opinions of his own. There's also the fact that throughout the novel he's referred to as a "boy," "lad," or "youth," even though he is at least eighteen.
- Kino of Kino's Journey turns out to come from a country where all adults are examples of this -- they're given surgery to become adults, rather than allowed to gain genuine maturity and wisdom. Their apparent adulthood turns out to be nothing but the thinnest of veneers, and any real stress or deviation from routine reveals them to be little more than children in adult bodies, going through the motions of maturity. The scene where they childishly fumble for the "mature" way of dealing with one of them murdering the original Kino in what amounts to an overgrown temper tantrum is horrifying.
- Lennie Small from Of Mice and Men.
- The title character of Billy Budd is a textbook example.
- Zhou Botong of the Condor Heroes martial arts novels is the Trope Codifier for Chinese literature. Despite essentially being the co-founder of one of the story's pivotal martial arts sects, he'll sneak off for fun at any given opportunity, making friends with the much-younger protagonists while imparting his unique brand of wisdom to them. Sex as Rite-of-Passage is averted early on, as the fact that he sired a child with an imperial concubine, while his fellow disciple (the founder of said sect) imparted a powerful technique to the Emperor, not only forms part of his backstory but arises later as an important plot point. On top of that, he's incredibly long-lived and one of the novel's most powerful characters.
- In Death: Poor Alice Lingstrom from Ceremony In Death turns out to be a child in a woman's body. She was just exploring Satanism and got involved in a Satanic cult. The cult drugged her and then gang-raped her. She was pretty much made into the cult leaders' slave for a time, but she left when she witnessed the two leaders sacrifice and murder a young boy. She actually thinks a spell had been cast on her, and that one of the leaders is a shapeshifter. Considering that she is suffering from trauma and paranoia, it is safe to say that her status of Womanchild is being Played for Drama.
- Sisterhood series by Fern Michaels: The Vigilantes seem to act like womenchildren a number of times. At least Myra Rutledge and Countess Anne "Annie" de Silva have the excuse of being rich 60-something-year-old ladies who may have never developed maturity...or they lost it as they got older! Cosmo Cricket, introduced in Final Justice, could be considered this. However, he has wisdom and is quite responsible in his job as a lawyer!
- Bertie Wooster from Jeeves and Wooster. His valet is implied to be acting as his Parental Substitute, and he's very childish in general—loves playing in the shower "like a two-year-old", doesn't know how to deal with women, and never got over his fear of his Grande Dame aunt.
- Lieutenant Wes Janson of the X Wing Series is a classic example, between his pranks, general irreverence towards everything in life, and his boundless sense of humor. He is capable of being serious, when actively shooting at things, but it's not his natural state. However, he explains that this is a deliberate part of his philosophy of living life to its fullest, given the mortality rate of his chosen profession.
Janson: I want you to remember something very important: you can't look dignified when you're having fun.
- Tigger comes off as this compared to the other animals in Winnie the Pooh. He's even sillier and more irresponsible than the other characters, he lives with Kanga, and he's best friends with her infant son, Roo.
- Lieutenant Panga in Someone Elses War.
- Bonanza: Several episodes have featured characters who were mentally "slow" – some villians, some sympathetic characters, others one-off good guys the Cartwrights aim to help. One of the best-known examples was "The Ape," from the show's second season, where a large man named Arnie has traces of autism, is unable to read social cues and (more worrysome) has a fierce temper. His fierce determination to win over a barmaid that has no interest in him is what eventually leads to his downfall, despite Hoss' own determination to help focus Arnie and mentor him into a farmer.
- Jacob from Lost began as an immature, emotional man with little social skills, plus he lived with his adoptive mother for nearly thirty years. Centuries later, however, Jacob's outgrown his previous phase.
- Has he though? "You've got ink on your forehead."
- TV's Frank from Mystery Science Theater 3000 is this part of the time, and at other times he's a knowing parody of it.
- Buster Bluth from Arrested Development.
- Randy from My Name Is Earl.
- Pretty much all six of the main characters on Friends, but especially Joey.
- Tom Baker, quite probably the most famous Doctor Who of them all, attributed his success in the role as having been that he played it essentially as one of these ("Hello! Would you like a jellybaby?").
- Mr. Bean is of the more common, Fish Out of Water type, although his strangeness goes beyond childlike and into the realm of truly bizarre.
- Sarah Silverman's character in The Sarah Silverman Program.
- Kirk from Gilmore Girls.
- The Big Bang Theory: While all the characters indulge themselves in childish things, Sheldon insists that someone take care of him the way his mother would when he's sick, (or even just homesick) locks himself in his bedroom where no one else is allowed when he's furious, curls up into a crying ball of sad on his bed when he's embarrassed, runs away from home when he's upset, is practically traumatized by the sound of people arguing, and is stubborn and petty beyond all reason. The only thing on this planet that can force him to behave rationally when he's angry or depressed is an order from his mother, who Lenard calls "Sheldon's Kryptonite". He also responds positively to being patronized by Penny, especially if he gets a toy robot and a comic book out of it.
- Dougal from Father Ted.
- Andy on Parks and Recreation. Part of the reason the show is praised for Growing the Beard is his Character Development having him go from a Jerkass to simple man who just doesn't know better.
- April of the same show fits as a Woman Child.
- and now they're married and live in the same house that they never clean, repair, or pay for. Ben has to babysit them.
- Tom and John-Ralphio also fit. They started Entertainment 720 together so they could look cool. The business tanks into debt in about 2 months because they didn't know that companies have to make money.
- April of the same show fits as a Woman Child.
- Radar in later seasons of his time on M*A*S*H.
- Stuart of Mad TV. Although the character is supposed to be an actual child, he appears as one of these because he is played by an adult man.
- On Fringe, Walter Bishop is a curious example of this. As a young man, he was a normal, mature adult. But then his partner cut pieces out of his brain and he spent 17 years in a mental institution straight out of Victorian England (okay, not quite that bad). The new Walter Bishop, while he retains his prodigious intelligence, is a Cloudcuckoolander who cannot manage the basic necessities of life on his own, and is dependent on his adult son and his FBI-agent-turned-lab-assistant to provide for his needs. While his foibles are often played for comedy, later episodes also play up the pathos of his situation; unlike most Man Children, Walter remembers having been capable of living on his own, and his humiliation and sense of loss are keenly felt.
- The IT Crowd - Moss is a man in his thirties who acts and speaks like a 4 year-old most of the time and still lives with his mother. Roy to a lesser extent.
- Cupid on Supernatural.
Castiel: "I found a liquor store...and I drank it." (falls onto Sam)
- Dean Winchester is this whenever the writers decide to take a break from angsting him. For example, he gets super-excited about classic monsters like a proper werewolf, and makes movie references non-stop.
- In Bad Day At Black Rock, while his run of luck allows him to have incredible reflexes and aim, Dean says "I'm Batman" after taking out an assailant, and looks genuinely disappointed/hurt when Sam responds with a "Yeah right, you're Batman".
- In Season 6, Dean also shows his childish excitement of classic Western movies and the opportunity to go to the good ol' West.
- In one episode of Suite Life On Deck called The Starship Tipton, George Takei played a descendant of London named 'Rome Tipton'. He is usually seen with a teddy bear and acted very much like London. He was even still in school.
- Stephen Colbert's onscreen persona is like this, especially at the Rally to Restore Sanity and/or Fear.
- Vince in The Mighty Boosh is constantly eating sweets, writes in crayon and has an imaginary friend made out of bubble-gum called Charlie.
- His actor Noel Fielding is of course very similar - in interviews and panel shows he will sit smiling sweetly, making silly jokes about rainbows, pigeons and pencil cases and acting like a total Cloudcuckoolander. This often leads to people making fun of him, and learning the hard way that he's also a professional comedian with a truly acid wit.
- Spencer of iCarly.
Spencer: "I hate that channel! They always make adults look like buffoons!"
- Burger, Ash and to a lesser extent Derek Jupiter of I'm in The Band.
- The Law and Order: Criminal Intent episode "Cruise To Nowhere" focuses on a young (about 20 years old) poker genius named Joey Frost, who acts like a petulant child and whom Goren describes as having the emotional maturity of a ten year-old. It eventually turns out that there's a sympathetic reason for this behaviour: a horrible childhood.
- Goren himself fit this trope in the early seasons. Witness, for example, his glee at discovering a synthesizer that says things like "Oh, baby!" when you hit the keys.
- Sometimes in later seasons, too, such as in 'Vanishing Act' when he reacts with similar glee at the various magic trick thingies.
- Pierce Hawthorne on Community, bordering into Psychopathic Manchild territory.
- Herman Munster. He frequently throws foundation-shaking temper tantrums.
- Dollhouse has Topher Brink who, for his mid/late-20-somethingth birthday, creates a buddy to play video games and tag with him. He gets much, much more childlike post-series tragically.
- Then there is Terry Kerans, who is listed amongst the Psychopathic Man-Children.
- Phil from Modern Family.
- Shaun Murphy in The Good Doctor is a genius level physician but he is a child emotionally. He has Autism to the point of keeping his room in obsessive order to befit a West Point drill team.
- A lot of his "childlike" air comes from his charm and innocence as well as his sometimes painful frankness. In point of fact normal children are more capable of deceit, cruelty, or petty worldly vanity then he is(he can barely lie, he has no ill will toward anyone, and doesn't care worth a cent about social dominance competition).
- The Idle Race's "I Like My Toys", which deals with a thirty-one year old man's desire to play with his childhood toys instead of looking for a job, much to his parents' chagrin.
- Blink-182's "What's My Age Again?" is about a 23-year old who is about to get laid, but he gets distracted by the TV, so the girl leaves, and he prank calls her mother in retaliation.
- In the movie The Wall, it's implied that Old Pink is one. For example, when a girl seduces him in his hotel room, he responds by trashing up the place; in "The Thin Ice" he's seen watching a Tom and Jerry cartoon on the TV; and, in "Is There Anybody Out There?" when he's building a mandala/replica of a military barracks/whatever it's supposed to be, a battery-powered toy robot is visible among the props.
- Tobias Ragg from Sweeney Todd: The Demon Barber of Fleet Street can be played several ways, and this is one of them. Bonus points if he is still childish because of insanity and/or mental retardation, both common portrayals. The Movie made him an actual pre-pubescent boy, a method that is much harder to pull off on-stage, mostly because labor laws require underage performers to be doubled.
- The clown in Cirque Du Soleil's Saltimbanco, Eddie, is quite childlike as he pulls pranks on others and engages an audience member in a pantomimed Wild West shootout. In fact, he might actually be the adult form of the Child seen early on, if a transitional scene is anything to go by.
- The Green Role from the Reduced Shakespeare Company's Ragtag Bunch of Misfits. Being the Man Child of the group is his defining characteristic.
- One interpretation of N's character in Pokémon Black and White. It's not played for laughs. Indeed, it may actually be Foreshadowing of his... father issues.
- Tingle from The Legend of Zelda series. A 35 year old man who believes he is the reincarnation of a fairy and spends his spare time floating around on a balloon searching for fairies. Ramped up in Wind Waker, where his HQ is a tower where his cohorts spin the top around to make magic happen....or something.
- Corpse Party has Yoshikazu Yanagihori, former Cool Teacher. As his mental illness progressed, he reverted to a childlike mental state, and eventually couldn't even convey his thoughts. People noted that he was still the same person he was before, so it was shocking when he apparently abducted four children and brutally killed three of them. He didn't actually kill the children. He was manipulated into kidnapping them, but he was just an accomplice to the real killer...the surviving child, who was actually a malevolent spirit.
- T-Rex, the protagonist of Dinosaur Comics, is a Ditzy Genius Man Child.
- Xkcd has at least one strip about this.
- Parodied in the last issue of Mac Hall. Ian recalls this phrase as he moves into his post-college life (and segues into Three Panel Soul, Mac Hall's Spiritual Successor), but adds the rider, "But I unpacked most of them when I got there."
- CS Lewis, in a similar spirit, once said "When I became a man I put away childish things, including the fear of childishness and the desire to be very grown up".
- Ethan in Ctrl+Alt+Del.
- David Walkerton invokes this trope in order to avoid responsibility (and also partially due to a traumatic childhood event) and can actually be mature and insightful when the situation calls for it. However, even when the need for the facade ends along with the main plot, he continues to act the part, so it's also a legitimate part of his personality as well.
- There are a few of these traits in Kamina in Double K. Quoth captainosaka:
i like how kamina's plan seems to suggest that he's regressing back to the mental state of a vindictive third grader under all this duress
- Henry VIII as portrayed by Brian Blessed in Henry 8.0. For example...
- Gordon Freeman, as depicted in Freeman's Mind, was this the even before his mental breakdown, apparently acting immature the whole time he worked at Black Mesa and doing many childish things like playing racket ball in the anti-mass spectrometer and doing a cannonball into his bath tub. And, of course, there's the episode where he discovers a cart that goes around in circles at high speeds. He just spends a full minute sitting there pressing the button that sends it back and forth while screaming "Weeeeeeeeee!". Let it be known that there's an alien invasion the middle of all this.
- Zack in Echo Chamber, though it's partially explained by his Freudian Excuse.
- The Nostalgia Chick's best friend, Nella, is repeatedly referred to (by herself and others) as a "wo-Man Child."
- Philip J. Fry from Futurama has since the beginning of the series been the epitome of Generation X (or Y perhaps): A big 20-something man-child. He plays video games, watches TV, drinks soda by the gallon, does crazy things off of dares, and has no ambition in life except for one...love. He's that flat mate that you knew who just can't seem to truly grow up (...and is often fully aware of it. Refer to his one ambition for why this is a source of gloom for him often), but at least he's cool to hang out with.
- The new season reveals that Fry is 35. Adult Child, ho!
- Actually, he might be as old as 31 since in one episode, he and the Planet Express crew were affected with chronotons that reversed their aging and then they negated the effects by going into the Fountain of Aging. And they, sans the Professor were reborn in the series's revival.
- Let's not forget that Fry is his own grandpa and that caused genetic damage, which caused his brain to develop abnormally.
- Also, Zap Branigan, though that's more disturbing as he is in a position of power, with the authority to get people killed in mass amounts.
- Peter Griffin from Family Guy.
- SpongeBob SquarePants.
- Patrick Star even more so.
- Toki Wartooth from Metalocalypse. He has a teddy bear, eats candy, collects model airplanes, says "Wowee", and has a childish naivety for certain subjects such as sex. He also drinks, swears, and goes on the occasional murderous rampage.
- Kyösti Pöysti in Pasila.
- Randy Marsh, Stan's father from South Park, has become this in recent years.
- Jasmine's father, the sultan, from Aladdin. At times he acts very childish, such as collecting toys and getting really excited when riding the carpet.
- The Warden of Superjail. And how!
- Timmy Turner will apparently become this in the future, according to his show's Live Action Adaptation, as pictured above.
- Every adult in Dimmsdale is this.
- Ray Stantz, one of The Real Ghostbusters, is a more subdued version of this trope. While mature and perfectly capable of looking after himself, Ray still possesses an almost childlike idealism and enthusiasm for life. Ironically, this actually helps the Ghostbusters lure the Boogieman when they learn that the monster is attracted to people who think like children.
- Luanne Platter from the later episodes of King of the Hill when she began dating and eventually married a moronic, middle aged, hillbilly "Lucky" to the point where she acts like a five year old most of the time.
- Peggy Hill was once described as a woman-child, possibly due to her self-centeredness.
- Most of the adults are immature in some way, to the point where Bobby snaps after his grandpa and step-grandma leave him to care for grandpa's infant son and Luanne and Lucky prove to be ridiculously irresponsible parents (I think Luanne is pregnant at this point).
- Hank's boss, Buck Strickland, is so childlike to the point where Hank always have to bail him out whatever trouble he gets into.
- Dexter's Dad from Dexter's Laboratory.
- The Earl of Lemongrab on Adventure Time is an interesting version of this. Physically he's eighteen at the youngest, but because he was born in a laboratory, he's only about one year old chronologically. He acts like a bratty little kid trapped inside the body of an adult, mainly because he IS a very young brat who happens to be an adult, too.
- Word of God on Madagascar and The Penguins of Madagascar is that Ridiculously Cute Critter Mort the mouse lemur, who looks and acts like a child, is the lemur equivalent of a thirty-five-year-old. Julien has tendencies this way as well; he's constantly demanding attention and throws tantrums when he doesn't get what he wants, but at the same time gets very upset and starts talking to his plush toys when he's lonely, and it's revealed via the magic of the Golden Squirrel that his greatest desire is simply to have his friends near him.
- Dr. Doofenshmirtz from Phineas and Ferb is physically in his 40s, but mentally around 8.
- While he technically isn't this yet, Debbie Douglas expresses hope that her son, Duncan becomes one of these in Freakazoid! because he's not exactly opposed to it.
Debbie: "You'll be a big strong man-child, still lifting weights in your room when you're forty!"
- Prince John from Disney's Robin Hood. He's very whiny, often throws temper tantrums, constantly sucks his thumb and cries very easily.
- Prince Charming from Shrek 2.
- Glickenstein and King Malbert from Igor.
- Waffles, the horned toad from Rango.
- The titular character of Johnny Bravo. He's in his mid to late 20s, still lives with his mother, throws temper tantrums when he doesn't get what he wants, spends much of his time playing with toys, has a lot of childlike interests, and he sleeps with a teddy bear and baby blanky often while sucking his thumb, on the other hand he's pretty perverted and constantly hits on women.
- Pops from Regular Show
- Rigby is this too. He may be 23, but he acts like an out of control teenager most of the time.
- Mordecai, to a lesser extent. He's a lot more level-headed and less impulsive than Rigby, but just as eager to slack off and do childish things.
- Oggy from Oggy and the Cockroaches.
- Lucius from Jimmy Two-Shoes.
- Humphrey from Alpha and Omega has signs of this.
- "Baby Brent" in Cloudy with a Chance of Meatballs certainly comes across as one. He's the same age as Flint, doesn't seem to be doing anything with his life besides being popular, and still acts like a schoolyard bully. That he still reenacts the commercial he appeared in as a baby, diaper and all, seems to be a serious case of Lampshade Hanging.
- And on the other hand there's Flint himself, who put fake security equipment in his lab and pretends to use it when he comes and goes. Even the kids in the neighborhood think he's weird.
- Richard Waterson from The Amazing World of Gumball. If anything, he's even more immature than his own offspring.
- As with the comic example above, Captain Marvel in Young Justice is really a kid. However, none of the teens know his real form, so he definitely comes off as being this trope.
- Thundercats: At the beginning of the series, Lyon-O was placed as a child in a pod to keep him from aging while Jaga drove their spaceship to the third planet. Unlike the pods of the others, his didn't keep him from aging, so he eventually left it as an adult, thus making it a case of Justified Trope.
- Xiaolin Showdown: Kimiko's Dad is a child on the inside. Or so she once told her friends.
- Michael Jackson.
- Andy Kaufman, in Real Life, was a borderline case. On the one hand, he was quite worldly (certainly no virgin) and capable of orchestrating and pulling off a substantial array of elaborate hoaxes on and offstage. On the other, rather than putting childish things behind him he just adapted his childhood pleasures into his adult life and work, and approached both with a certain childish stubbornness.
- 1970s baseball pitcher Mark Fidrych.
- Peter III Of Russia was said to be this by his enemies. Instead of consummating his marriage immediately with his German wife he would play with toy soldiers in the wedding bed, and once hanged a mouse for treason. He also had a very child-like fascination with his hero, Frederick the Great, which ruined Russia's successes in the Seven Years' War. Unfortunately for Peter, his wife turned out to be Catherine the Great, and he was deposed by her and her lovers in a very smooth coup.
- Guitarist Buckethead could be considered one. His stage persona is very child-like in behaviour (or maybe the man himself is). He also seems to enjoy toys and scary puppets.
- Canadian government minister John Baird is known around the House of Commons for his lack of an inside voice as well as frequent outbursts/tantrums on the floor of said House.
- Jeremy Crispo, who is obviously obsessed with and defends Barney and Friends.
- Wolfgang Amadeus Mozart.
- According to anecdotes in Reginald Pound's book, "Surgeon Extraordinary", pioneering surgeon Harold Gillies frequently did things that were really childish, like standing on his head to "rest his feet" or at one time climbing onto a car and wiggling his foot in an unsuspecting passenger's face (it was all there in that book!). However, this trope is subverted in that otherwise, he was a pretty smart guy.
- Christian Weston Chandler, of Sonichu fame.
- Donald Trump. Enough so for movements in several countries (most prominently UK in July 2018) to make baby balloon caricatures of him.
- Although this one may be perfectly justified, as his parents often got into arguements when he was a child and it is also implied that a lot of the arguments were exceedingly violent (he mentioned that his father would start throwing plates and shattering them in the kitchen, and that his mom planned to place glass shards in his father's meatloaf), even when they said to Sheldon that they stopped fighting