>>57985359 (OP)Well, anon, I think you're old enough to know this. You see, in the Pokemon world, all teenagers go through a hormonal period, and to satisfy those needs, they use the "help" of Pokemon. Don't judge, these are their customs, being more of a temporary rite of passage. Among these, the most popular is Ditto, which can fulfill any fantasy. The thing is, sometimes this produces an egg, and as is the custom of irresponsible teenagers, they abandon them in the forest.
Ditto's body is adapted to replicate the DNA of any Pokemon and obtain an egg with those characteristics, but when Ditto is "used" by a human, it cannot fully adapt to human DNA and ends up replicating an egg with a Ditto inside.