Very entertaining post, Plynkes; thank you.
May I add a fave monster from my country? The Xhosa people (Mandela was one, btw) have a water-dwelling homunculus known as a tokolosh. He looks like a diminutive human, but can live underwater, has enormous strength, and has a ridiculously long and prehensile male appendage which can be sent through a window or under a door to rape sleeping men. Even today, it is not unusual for a Xhosa man to claim to have been the victim of such treatment.
The tokolosh dislikes being talked about. I had a Xhosa nanny in my youth who refused to say more than one or two sentences about him lest he strangle her on her way home. I've also read that when he kills he leaves no mark, but this was in a work of fiction (not written by a Xhosa), so I don't vouch for the authenticity of this belief.