The Legend of the Kuchisake Onna - The Slit-Mouthed Woman - Vol. 1 Ch. 3 - Snail with No Shell

[MangaDex]

 

[Tikibo]

Like slugs weren't gross enough by themselves... Also, why the hell

Spoiler

bunch of slug-men lived near the sea

?

 

[Vainfire]

The sea is traditionally the birthplace of such benthic horrors as the Deep Ones, or WWII-era biological weapons, etc. The seaside village is a traditional locale in horror stories, almost as traditional as the heart of metropolitan decay or an apartment complex. This, then, is a very traditional story. Classic body-horror/psychological horror of "humans but they act weird and look different". Pretty good.