okay so I came up with this idea long before season 4. Possibly after I first watched the show (which was after season 2). And while its aleady poven wrong, theres a couple things I want to add to theories about what's happening in season 4, but i will put those thoughts (and any season 4 spoilers) under a cut. But the rest you can read as a story idea or au if you want

(Also, sorry for typos and lack of capitalizing, I typed it in a note app first and it doesnt automatically capitalize new sentences)

ok ok so this idea is basically MK is a stone egg baby kinda based on the idea of hatching an egg under a toad makes a basilisk, but if you sit a mystic monkey on a rock and have him wish for a successor he hatches one ANYWAY idk if this stone is already magic or not. but wukong sits on a stone on a mountain near the city and looks over the city. he admires the view and kinda wishes how he had someone to spend it with. but also he's lonely and maybe is kinda preparing to end his immortality. but he doesnt want to leave the city/world unprotected, and that maybe he could train someone to take over for him. but this is all just a passing thought! he barely even realizes that he thought it! he turns into a bird and flies back to ffm little does he know that in his thinking, some of his magic was absorbed by the stone. but that alone isnt enough to hatch a baby.

the stone sits on a hiking trail. A hiking trail that a certain pig likes to hike when he needs to get out some of his frustration when it's been a bad day in the noodle shop. He likes to sit on the nice big stone and look at the city. He can see his shop from here and he knows no matter how bad a day he had, the shop is worth it. And maybe he thinks about how the building had been passed down through his family, but who was he going to give it to? (not that he's anywhere near old enough to give up the shop, but… he didnt have any family.) hmmm maybe he should hire some help? hmm other places deliver. maybe he could get someone to do that? absent thoughts, and relief gained, the pig continues home. none the wisher that the stone has taken in his thoughts and wishes

And maybe the pig comes back on the trail with a scholar to show him the view, and maybe the scholar complains about his ankles and asks to sit down. and maybe he starts to tell stories of the Monkey King and maybe the pig is a little less than attentive , and the scholar wishes for someone who enjoys the tales as much as he does. And after they finish enjoying the sunset they continue on their way. none the wiser to the stone that holds warmth from more than just the setting sun.

More people come and sit on the stone to look at the beauty of the city and bask in its warmth. A couple with their baby daughter who has too much energy for their house of collections. A big blue guy who is trying to cool his temper by going on hikes and befriending the wildlife. and maybe they all come back at various times. and they sit on the stone.

And the stone has been storing their energy and wants and desires until one day

one day the pig is hiking to his favorite spot. but before he gets there he finds a little lost child on the path. who would just leave a child on the trail?? he takes the child back to the city. no parents are ever found and well, they've gotten a little attached to each other. it's not for another couple months that he has a chance to go back to the trail and is very disappointed that his favorite spot to sit is no longer there. (who moves a stone?!)

As for the monkey king. maybe he senses something (but doesnt know what exactly) when the stone hatched. or maybe he's observing the city again when he's drawn to a noodle shop. Inside he sees the pig and the scholar and a child. He thinks what ever he sensed was the pig and scholar, since they so closely resemble his old companions. However the child steals his attention as he climbs the stool onto the counter to swipe the noodles from a bowl with out the other two noticing at all. the King finds the kid amusing and decides to check in on him anytime he decides the visit the city. and finds he does so more and more often and the kid reminds him of himself.

And as the years go on, he thinks that maybe just maybe, he could retire and this kid could be his successor. yeah, that seems like a good plan! the kid was just like him, but also better. who better to give his powers to?

SPOILERS FOR SEASON 4 BELOW

okay. so obviously this idea is wrong firstly in that in canon MK's stone came from Moneky King's stone, whereas my idea had it be a completely different stone.

Canon also makes it seem like someone deliberately made MK. But I do wonder if the person or whoever or whatever realized what they were doing though, and didnt realize they succeeded and that's why MK was able to just wander up to Pigsy's shop. Maybe. Idk

I DO THINK that the whole reason Monkey King started watching Mk was because he sensed Something about the kid (even if he didnt consciously realise it or pinpoint what exactly he was sensing) and decided to keep watching him. And after a while decided that if anyone would be his successor it should be this kid! (Genuinely unaware of the link they share)