“ During a storm the PCs come upon a little boy that plays in the rain. Upon further inspection they discover that he has one eye and a long tongue lolling in its mouth. Spit dripping. It is a demon from beyond that can access our realm during storms, it eats all heads that are not its own, living and dead.”
“ A certain patch of forest is well known for causing anyone who ventures into it to suddenly go blind. Once they leave the area their vision returns. Rumors of treasure hidden within.”
“ 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.”