“The great hulk of the scaled beast lay wheezing before me, and I am not ashamed to say that I was frightened: though it was injured, I knew the dragon could easily tear me in twain. The young monk, however, knelt beside the creature’s head, whispering to it in a strange growling tongue. I questioned the woman, but she ignored me completely, engrossed in examining the scaly monster. After much badgering, she said merely, ‘I do not mean to be rude, but you are quite a distraction. Please, leave me to my work.’” -Jeron’s Great Journeys, Book III, Chapter 4
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.