Not sure where to post this, it's just sort of interesting. This guy apparently tracked down the origin of some of the more obscure monsters in the Monster Manual, in Dungeons and Dragons. Like, the owlbear, the rust monster, and the bulette. Apparently they got started as cheapo little rubber and plastic toy monsters, made by some company in Hong Kong for little kids back in the early 70's. I think it is interesting that the company apparently just made up their own freaky little monsters, they gave their creative guys free rein to just have some fun and just go wild. I think in more modern times, there would probably be pressure to just make little toy versions of recognized, pre-copyrighted franchise monsters that are already very popular... Anyway, the Hong Kong company monsters just came all together in groups of ten or fifteen, in plastic bags, and they didn't even name the monsters. Then, it sounds like when Dungeons and Dragons was getting started, they were looking for new kinds of monsters they could stick in the games, and somebody literally just went to the 70's equivalent of the toy aisle in a modern CVS store, bought a bag of rubber and plastic monsters, took it home and made up background stories, traits, hit points, etc for all the monsters. If anyone here ever went through a D+D phase in your life, you might find this interesting.
https://diterlizzi.com/essay/owlbears-rust-monsters-and-bulettes-oh-my/