>>39923903My theory: Ultra Beasts were originally going to be in Pokemon Z as mutants from the apocalyptic future Lysandre was trying to prevent. Celesteela resembles the Ultimate Weapon and is an artificial plant (sometimes a trope seen in sci-fi when a planet's real flora has gone extinct), Guzzlord resembles Zygarde Complete, Pheromosa is a take on a standard post-apocalypse trope (giant mutant cockroaches), and Xurkitree might be inspired by the machines from the Matrix (I admit this one is a stretch). The whole
>Are they Pokemon or not?mystery would've worked a lot better if they were mid-gen additions, since such a thing was unprecedented.
But since Z never made it past pre-production, they were retooled into aliens, Nihilego was created for the SM storyline, and Buzzwole and Kartana were created as counterparts for Pheromosa/Celesteela. Blacephalon was possibly originally planned to be Xurkitree's counterpart, but that's a whole separate theory.