I might have thought this distinguishing feature of Japanese youkai comes from the marginal existence of most people through Japanese history (see The Ballad of Narayama for a notion of how marginal Japan could get- and that was set in Meiji.) But China has had famines since time immemorial and they don't do the grotesque glutton thing. I conclude, disapprovingly, that people who only want to EEEEEEAATTTTT!!! is just something that tickles the Japanese fancy, like bathroom humour.
The only intriguing youkai I know of is somewhere in Yumemakura, a toss-away story of Hiromasa's about how someone saw a horse-headed youkai, tall as a house, walking down a street in the moonlight reciting a Buddhist mantra. Hiromasa was quite admiring of the youkai's devotion, as he should have been. If there were more youkai like that around I might be able to write 100 Demons fanfic. As it is, it's like writing about orcs or kobolds: no story there at all unless it's about How Wonderful Us Defeats Disgusting Them. And whenever a Them crops up in a story alarm bells sound. Who are They *really* meant to be, hm? If you can't take the pov of all your characters, at least theoretically, there's something wrong with your story, say I. And I can't take a youkai's pov at all.
