This is a fantastic thread -- I have been engrossed all afternoon, especially by Tattoo Ted's tales. I never get tired of this sort of thing; here's my tuppence worth -- my mother (somewhat sadistically) told me the following fantastical account when I was quite young, and still swears by it to this day.
WARNING: LENGTHYISH!
When my mother was 9 she woke up in the middle of the night to see what she describes as "a devil with huge yellow slanting eyes" crouching in a corner of her bedroom ceiling. When she asked it what it wanted, it laughed and said "I'm going to make you so ill". Now, my mother was a hearty, rosy-cheeked tomboy rude with health (and just plain rude, according to her teachers), so she scoffed at this, saying "Besides, my parents wouldn't let you."
The "devil", evidently amused by this, picked her up off the bed and swung her round the room by her hair(!); apparently she could feel her arms and legs hitting the walls and ceiling; the racket seemed to wake her parents, who rushed into the room to find their bruised daughter alone but in a state of distress, half off the bed. Anyway, it was decided that it had been a nightmare (the bruises put down to my mother's nocturnal habit of kicking anything within 2 feet of her) and duly forgotten.
However. About a week later she came down with a severe and prolonged fever, she lost weight, then consciousness, her skin turned yellow and she seemed to be in intense pain. The doctor diagnosed 'flu, then jaundice, then malaria (this was all during a summer in Nepal), then admitted defeat and sent her to a large private hospital; specialists were called in but her condition worsened rapidly and no one held out much hope.
It was at this point that, in her delirium, she saw the "devil" again, crouching on the wall in her hospital room, and he told her "it's such a shame you're going to die", laughed, then disappeared, but my mother was too weak to care much. Later on during the same night (she thinks), she felt the end of her bed depress, and she opened her eyes to see an old man in a linen jacket with wooden buttons smiling at her. He put a cool hand on her forehead, and said something like "it's all right, he won't come back now, go to sleep" -- she drifted off and the next morning her fever broke and began the long road to recovery.
And it was a long recovery -- it was at least a year before she could walk again, and in that time the family returned to France (she's half Nepalese and half French), but she has no memory of the journey. The experience hasn't left her unscarred -- she's never been 100% healthy since, and some years ago, before he died, her father revealed that *his* father -- my mother's grandfather who had died before she was born -- had been fond of wearing a linen jacket with wooden buttons.
I'm a hardwired skeptic, so I've never known exactly what to make of this story -- both my mother and maternal grandfather (now deceased) have attested to it, though. And it scared the *hell* out of me when I was little...!