Many of them (e.g. https://en.wikipedia.org/wiki/File:20190922_Mollisonia_pleno...) are angled similarly to how an opponent would be in-game (I guess prior to Gen 9 with its free camera).

Anorith[1] and Kabuto[2] are based on anomalocaris and xiphosura (horseshoe crabs)

[1]: https://bulbapedia.bulbagarden.net/wiki/Anorith

[2]: https://bulbapedia.bulbagarden.net/wiki/Kabuto

My first thought was that this person would be an excellent consultant for some arthropod-based game or film (Arthropods Attack?)

I wonder how common it is for folks to try to understand some new field in order to build something vs. the other way around vs. just outsourcing that expertise.

These are really charming illustrations!

It's enough to make you want to have a pet arthropod, or a Pokémon game based on real creatures.

Aren't insects such as beetles somewhat popular pets in Japan, and wasn't catching and collecting a major inspiration for the Pokémon games? (Not to mention the bug catching minigame in Animal Crossing?)

They're kind of underappreciated in the US, which is too bad.