One cool idea I remember from the setting, though, was the way monsters were conceived. I don't mean in the "dim lighting and lots of booze" sort of way, but all of the monsters that I remember being mentioned were once Men that had been cursed by the gods, which as you might have gathered from the book's title, were crazy. And not just because they dropped Coke bottles from the sky.
My hazy memory tells me that each breed of monster was monstrous because the gods had stolen something from them that made them human. So these Men-driven-mad wandered the highly-dangerous wilderlands outside of the villages in a very much "Points of Light" kind of way, and each one had different behaviors and [twisted] desires that drove them. All of them, the shamans said, were murderously jealous of Men...
Bearing that in mind, I jotted down a list of monsters like this, just to see what I could come up with:
Obviously, some of them are more Fiend Folio 1e-worthy than others, but some of them, I think, have some creepy possibilities. A lot of them struck me as horrors from "Silent Hill," all mottled skin and flesh-masked stumbly freaks. If you go beyond the obvious handicap of a missing body part and read it as more metaphorical, you can end up with some pretty unpleasant terrors.