Consider the idea of spontaneous genesis of life, as used to be belived. What strange kinds of life might arise from modern substances? What kind of vermin would a landfill produce, or an oil spill on the ocean?
A demon who isn't some hideous creature bent on consuming souls, bu is, in fact, a likable chap who enjoys having pleasant chats with people - trying to talk them into becoming his servants.
"The world has an immovable dark red sun in the centre of the sky that produces very little light. The heat is totally unbearable and the aroma of delicious cooking meat is in the air. To look around it appears as though you are surrounded by giant black mountains with no vegetation anywhere. The ground is soft and an oily liquid flows into your footprints. Travelling reveals nothing else."
Any character without some resistance to fire or heat is slowly being cooked. The ground if you haven't guessed it is the cooked meat.
I've wanted this world to be part of a dimensional hopping "chase". I thought maybe to populate this world with giant carnivorous beetles or perhaps this could be a "Nirvana" for deceased or living (but dimension travelling) fire dragons.
Perhaps I've just been grilling a little too much meat or perhaps there are some great ideas out there on how to spruce up the place. Any suggestions?