“ Thunder and lightning is the sign of their shamans hunting and killing demons. Children's souls must be protected for their souls are not firmly in place yet and are easy for demons to take hold of. The shamans must hunt and destroy them and each break of thunder is another death of a demon hunting for souls.”
“ A desolate region is almost entirely without normal vegetation. Local plants are able to unroot themselves and crawl along the ground in search of water and fertile soil. The inhabitants fence their crops in to keep them from wandering off and put heavy stone thresholds in the doorways of their huts to keep wayward plants out.
The plants sense by chemical cues, lacking sight or hearing, and tend to avoid herbivores or anything that smells of 'dead plants'. Characters with horses are likely to be unwelcome among the locals.”
“ If you want to add a 'supernatural' touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.”