I want to make a manchild character but I don't want him to be obnoxious, so I want to know what will makes people actually like manchild characters
I don't know any likeable manchild characters. The term itself implies a negative image. You can have likable childlike adults, but that's different.
Are you talking about a guy with adolescent pastimes? Or is he dangerously irresponsible. I picture a frat hero of the last generation still crashing parties. I'm curious how severe his sins are. You have to put yourself in his shoes. Even with the darkest villain, if you give him a chance to prove himself in even a small way, that is pretty redeeming to the reader. So don't make it a complete caricature. Maybe the people around him see one thing, his edgy, carefree behavior, but then the reader sees something deeper, some dark concern or heavy responsibility that no one knows about. Perhaps he's venting with a flippant or trivializing behavior, or even trying to distract others. Maybe he's distracting himself. Maybe he's running from a problem that's about to catch up with him. Give your characters the benefit of the doubt. Heck, that's going to shape the whole character and the plot.
Those around him may be sheltering him against his will. This could be well-intended or more sinister and self-interested. The latter wouldn’t even need to be conscious. A mother or father who can’t stand the idea of their widdle baby growing up and thus undermines his efforts to mature and become more independent, maybe. The Waterboy is actually a really good example of this one. Bobby Boucher is pretty much a textbook manchild, but his manner, the bullying he faces, and the fact his childishness is the result of isolation imposed by his zealot mother—who fears he’ll leave her like his father did—all endear him to the audience.
This is really good advice. I often write characters that are unlikable to the outside world but more likable to the readers because they can see other aspects the world can't. That's also why I use first person so often. It's a nice way to get even closer to the character. Though you don't have to use that POV if you don't want to. It's just something that I do.
Don't worry. His adoptive big brother just want to protect him, but since he end up sheltering him from harm, he grow up into a really naive adult who doesn't know the outside world, especially since his adoptive brother is an alien who take him from earth from early age and he doesn't really know his fellow human. His biological parents kinda abandoned him
I can't recall reading one I ever cared for. However, Andy from Parks and Recreation was a likeable man child. He was an unemployed starving artist type, who had big dreams but was lazy...initially. The type of guy kids love, because he's one of them at heart. Caring, but in a goofy manner, would write a silly song to win a girl over, but they usually backfire. I'd say a good start would be something along those lines. The favorite uncle that the parents all roll their eyes at. Sort of simple minded but only because they lack real world experience that you can give them along the way.
Every Will Farrell character, basically, haha. Not a big deal, but I wouldn't associate the term man-child with this. That definitely conjures immature, obnoxious, but probably fun-loving men doing inappropriate things in a pratfall kind of setting.
I think of "failure to launch" tropes. A guy who's twenty-two, wakes up at noon and plays XBox. (Living the dream.)
I hope this character doesn't become one of those characters that Adam Sandler used to play in the mid-90s. I tried watching "Billy Madison" and "Happy Gilmore" back then, but to me, Sandler's boyish charm didn't rescue either of those characters from being immature, lazy, moronic, and obnoxious. I agree with Louanne: Forrest Gump was much more likeable. He is a simple man trying to make sense of a complicated world. When things go wrong, his first instinct is to talk to mama, which is endearing. After his mama passes away, he goes to her gravesite and talks out his problems until he figures things out, which is poignant. (Maybe I'm remembering it wrong? I hope not).
That's the whole point of Adam Sandler's "appeal," for whatever that's worth. And that's how I would define a "man-child." One who is willfully immature and obnoxious. It's a pejorative term. Forrest Gump couldn't help it. I wouldn't call him a man-child. Very different connotation.
Originally I was going to suggest this was a simple fix, and it is. But there is small bit of nuanced to making this work and if you skip it, you miss out on a really great opportunity. The simple fix is you make the character likable the same way you make all characters likable, given them a universally accepted likable trait, their kind to animals, good with kids, spend time with the elder, are loyal, honest, dependable, etc. etc. etc. That is just the garden variety make a character likable stuff, sprinkle any of that on top and the character is likable (or more likable at least). But specifically with the manchild... you want to make the likable trait something that feels associated with being a manchild. So the manchild likes to play video games, so maybe he visits a local sick kid and plays games with him to cheer him up. Or if he's viewed as irresponsible maybe he spends time with his grandma and brings her favorite unhealthy snack food. If it is an act that is kind but not something an adult would not normally just do aka something a nice kid would do. It reinforces his manchild behavior but also shows he has good intentions and is a good person, his child like naïveté will be viewed as charming. People will love him for being a manchild.
