DMs: What's a bit of world building on the micro-scale you're proud of?

[Lord Torath]

Zoink. Stealing this. That's a good piece of lore.

When did gnolls become fiendish in nature? I always thought they were just hyena-inspired humanoids. I mean, yes, their god is a demon, but in 2E at least, they are purely natural beings.

I gave them hyenadon mounts/pets when I placed them on the Isle of Dread, a matriarchal society (same as real-world hyenas, as I understand it), and made them rivals to the Rakasta tribes.