How many ways can something turn into a monster girl?
We all know about mamomo mana, but that's just one method.
Can we consider non-humans with no relation to mamono mana monster girls like those infected by the miasma?
We know how the mamono mana in MGE can turn every girl, object and animal into sex-crazed husband hunting monster girls.
Then there's the Sandstar, a mysterious substance that turns animals into "friends".
Friends resemble humans while keeping their physical animal traits such as ears, tails, wings.
They are not as drastic in appearance when compared to MGE's girls.
The Snake Friends aren't lamias, they still keep their tails so they resemble more like lizards.
Snake Friends all wear hoodies, Tsuchinoko is one example of a snake girl.
Bird girls aren't harpies, they resemble humans with wings on their heads.
The mammal friends such as Grey Wolf (second image) are basic kemonomimi.
Sandstar energy only transforms animals and all Friends are female.
Are friends monster girls? I'd say that friends like Grey Wolf aren't really monster girls and that they are their own thing.
Sandstar isn't lewd energy, Friends are innocent.
Friends like Grey Wolf are not lewd and are not for sexual.
Outside of MGE, Yokai can be born in many ways.
When an animal lives many years and achieves immortality, it takes human form like Bakedanuki and Bakeneko.
When a cat dies, her ghost takes human form and grows another tail.
When an object gets really old, like an umbrella, it becomes a monster like Kogasa.
Even a human could become a Yokai under the right conditions.
2hus in Gensokyo are not lewd like the Monster Girls of MGE.
If mamono mana were to enter Gensokyo, all the 2hus like Ran and Reimu would change.
Reimu would be a Dark Priest
Suwako would be a Mucus Toad
Alice would be a Living Doll
Ran, Chen, Yukari and other yokai wouldn't change physically, however they become rapists looking for guys to rape-marry as their natures become hyper sexual.
The Scarlet Sisters replace their diet of blood and human flesh with cum and human cuddles.
Meiling becomes a Ryu
Sakuya becomes a Kikimora
Patchouli becomes a Lich
Only one that wouldn't change at all would be Koakuma since she's already a succubus.
Koakuma would just go with the flow and join in on the raping as is already in her nature.
There's also girls changed by the Behelit from Berserk.
They are bloodthirsty and would rape a guy to death.
If you value your life, then stay away from these girls at all costs.
Talk about other methods of transformation.