- The CollegeHumor Original "Adulthood vs. Childhood" has Adulthood and Childhood facing off in a fighting game, only to be interrupted by a third contender: the MANCHILD.
- Also, Amir.
- The Doctor (10th incarnation) in episode 5 of Ducktalez. When Dewey asks for his advice for the time travel situation, he messes around with his Sonic Screwdriver instead. During the stinger, he pretends his TARDIS is an automobile. He also shows up during the bowling montage in episode 7 and zaps Gizmoduck with his Sonic Screwdriver.
- DSBT InsaniT: Kayla is a female example. She is frequent to pout or use wrds like 'meanie' when she doesn't like something or someone.
- Alex is prone to throwing hissy-fits when things aren't going his (often twisted) way.
- Zack in Echo Chamber, though it's partially explained by his Freudian Excuse.
- 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 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.
- Jimbob in GEOWeasel is an adult man who is interested in such things as Nick Jr., trick-or-treating and waiting for Santa Claus.
- Henry VIII as portrayed by BRIAN BLESSED in Henry 8.0. For example...
- In the JesuOtaku/Nostalgia Critic crossover review of Digimon: The Movie, the later repeatedly called the former a "woman child" when they traded insults. The joke being he has no room to talk.
- The Nostalgia Chick's best friend, Nella, is repeatedly referred to (by herself and others) as a "wo-Manchild."
- The Onion: "38-Year-Old Little Boy Posts Picture Of Fast Car He Likes To Facebook".
- SCP-590 was turned into one by the SCP Foundation, specifically ordered by his brother Dr. Bright, by using his ability to heal several people suffering mental retardation until he had the mind of a toddler. This was supposedly done as an act of "kindness" so he wouldn't realize his predicament.
- Captain Sam Sweetmilk from Starship Goldfish, justified as a side-effect of erasing his memory, Vela is this too to a lesser extent, possibly due to being alone on a space station for who knows how long with only an AI for company.
- Talking Classics star Keith Apicary is a big one. He apparently still lives with his family, has No Social Skills, isn't too smart, a klutz, and spends his days playing and singing about video games.
- Guy and Ellers both from Chronicle Of The Annoying Quest. Though Guy is more cynical while Ellers is a Casanova Wannabe, they both have extensive arguments about Star Trek, Doctor Who and just about anything associated with geekiness, never really taking their quest all that seriously. James, unlike his brother Eric, is naive to the point of stupidity. Goliath frequently asks questions any adult should know the answer to, and exasperates his wife constantly with his immaturity (oh, and he's also responsible for crashing the Exodar). Finally, Stephi is a typical Dumb Blonde Valley Girl who thinks Dirim is her boyfriend. Basically a quarter of the series' cast fits this trope in some way.
- Sparadrap in Noob, to the extent of making him more of The Cutie than a female character that was his Distaff Counterpart before her characterization diverged but didn't completely split off. His top priority in a fantasy MMORPG is collecting non-combat pets, his Trademark Favorite Food is a dessert home-made by his grandmother and he tries to make friends with every single player he meets despite the game having a faction system. This is more than enough for both his guildmates and his younger brother to consider they need to keep an eye on him... or in the case of the Manipulative Bastard among his guildmates, pull some of her easiest scams ever. He starts maturing after an enemy player decides that it would be fun to destroy the bag containing his pets in front of him.
- The "Tendies" meme from 4chan parodies this trope, consisting of anecdotes that revolve around an autistic man/adolescent who lives with his parents and constantly terrorizes them by demanding praise and food items such as chicken tenders ("tendies"). Part of the meme also emphasizes the character's parents attempting to control his behavior with a childlike reward/punishment system known as "good boy points."
- Fictosophy: Tom, in "Jedi Coworker," goes to the office wearing Jedi robes.Steve: Tom should be ashamed of himself for acting like such a child!
- Sag from Movie Rehab got mature critical thoughs but he still acts like a kid at heart.
- Bee from Bee And Puppycat is in her twenties, though can't hold a job, is always messy, and acts immature.
Man Child / Web Original