Create an image of a Harry Potter Dementor hovering over a dark

Create an image of a Harry Potter Dementor hovering over a dark, misty swamp. The figure must be draped in its dark, tattered robes, with a sinister outline and continuous skeletal hands. The surrounding environment must be a desolate swamp, with gnarled, dead trees, murky waters, and a dense fog covering the ground. The lighting should be dim and gloomy, with an oppressive and frightening mood.