Although Pokémon has an incredible variety of creatures filling its world, perhaps some of the most interesting are actually artificial creations. One of the most notable of these is Mewtwo, the genetically-engineered Legendary of Gen 1, but Mewtwo is far from the only such Pokémon to exist. From deliberate design to accidental animation, there are many artificial Pokémon that owe their existence to humans.
https://screenrant.com/pokemon-like-mewtwo-origins-ai-creations/