Hanon-Tramp: German name for a classical type of nightmare. This particular nightmare took the form of a demon that suffocated people during sleep.
Old references to "moon demons", among other names, exist in art and literature. They are said to inhabit the dark side of the moon, and can sometimes take on physical form here on earth. The creatures are considered malevolent, small (about the size of a 7 year-old) pale skinned with large dark eyes. It is said a moon demon can emit such a scream that it will freeze a human or animal alike in terror.
Moon demons are more powerful, and more likely to be seen, during the waning moon.
