>>45058738Here's some L O R E no one ever points out but me.
Background: These 2 are based on amanita muscaria, the quintessential red mushroom with white spots you see everywhere in media. The REASON you see it everywhere in media is because it was re-popularized by the Alice's Adventures in Wonderland book. Prior to that, they were painted frequently in medieval paintings of fairies. For similar reasons, a lot of those garden gnome statues include them.
The common thread between all these things is that amanita muscaria are "magic mushrooms" that get you high. Specifically, the #1 thing they are most known for is making those who ingest them feel either a lot smaller, or a lot bigger than they actually are. If you take them, you'll feel as though you're a giant or tiny.
That's why they were depicted alongside tiny fairies and gnomes, as though taking the magic mushrooms brought you into their realm. It's why Mario gets big when he grabs a mushroom, and was why in Alice there were those special mushrooms that changed your size. They were in popular thought enough the the size-changing aspect often gets forgotten, and they're now the "generic mushroom" so you'll see things like Parasect vaguely looking like them.
Foongus and Amoonguss don't do the size-change thing (though Pokéballs do shrink and grow, at least in the anime), but you can see WHY they look like Pokéballs. A designer at GF realized that these mushrooms were red, white and round, and so were Pokéballs, so they incorporate that somewhat nonsensically into a design.
In X and Y, Laverre City is FUCKING FILLED with exactly these types of mushrooms and no other kind. It's the fairy city. Behind Laverre is the Pokéball factory. You find Foongus in hoards on the Route immediately after Laverre.