b. Bach's time machine in Opelucid, and the alternate universes involved in it.
And has NOTHING to do with what I originally thought it did.
In my imagining of the Pokémon world, there are real animals as well as Pokémon - with just Pokémon alone, there aren't enough to keep a realistic ecosystem going. Besides, that raises the question of where humans come from. No, my Pokémon world is our world - only with some superpowered monsters and five island nations shoved in.
Basically, the cat isn't a crossover from any other kind of reality, and so keep hoping. You might get what you wish for - or something like it.