>>42099262... and Gigantamax is explicitly a warping of Space-time by Eternatus' power (likely derivative of it being a) an alien god and/or b) it being the embodiment of gravity)
Even Ultra Beasts, alien as they are, still follow Pokemon's typical philosophy of combining traits that are similar or connected somehow, in a way that may not be immediately obvious.
Phermosa is a roach, but the opposite of how we feel about them - Beautiful and afraid to touch anything, contrary to how theyre perceived as ugly and untouchable.
Kartana is an origami samurai
Celesteela is a rocket ship, but foremost based on Kaguya-hime, the Moon Princess from the tale of the Bamboo Cutter.
So she's a Japanese princess, combined with bamboo, combined with a rocket ship because rockets take you to the moon.
Guzzlord is a black hole, but also a gluttonous dragon. Basically a movie monster.
Still, it's true that UBs are made to poke fun at the "this doesnt even look like Pokemon anymore!" view, by taking it to the extreme and making things literally not look like Pokemon.
