A couple days ago, Dealwithitdewott commented this on the Petit's Adventure page:
"I feel like there's gonna be a theory about the Muha Kids/Small Ghosts."
Even though it's already been confirmed that the Muha Kids are not actually kids, let's have some fun and make a theory about it.
Maybe one of the Muha Kids is actually the main character? Petit?
Think about it, the Muha Kids haven't actually been in a Petit game actually. Only graphics were made of Muha Kids.
And Petit and the Muha Kids have never actually seen eachother in the games yet.
Possibly, during an alternate ending of Petit Lost in a Cave, Petit was killed after the battle against Vometronz?
And there's something very weird.
The place Petit goes to fight Vometronz in Petit Lost in a Cave is somehow black. Why is it black?
Is it possible there was something wrong about that pitch black part of the cave?
Was there any black magic?
Could Petit have died after feeling the black magic?
Maybe after defeating Vometronz, he could no longer withstand the black magic and simply fell unconscious?
But you may ask, why does Petit keep appearing in subsequent games?
You could devise all games made after Petit Lost in a Cave take place before Petit Lost in a Cave.
This theory is non-canonical and should not be taken seriously.
In truth, Petit is not a Muha Kid and he shall never die in any official game.
And the reason Muha Kids have yet to appear in a Petit game is due to the fact, no game of the Petit's Adventure franchise features a level that suits the Muha Kids yet.
If a ghost-like level were to be explored in a Petit game, Muha Kids would be found there, and Petit would be exploring it.
Also, these games are kid-friendly, so no one will die but they are simply "defeated".
And the reason the place Petit goes to Vometronz in Petit Lost in a Cave is black is because that area is actually outside of the cave and it is nighttime.
And as for the timelines, not all games made after Petit Lost in a Cave take place before it. Check the Chronology article for more info.