This character is known to be a supernatural being derived from ancient myths, literature, and folklore. There are two different interpretations of the overall picture. The first being that the imp the image, is the source of the woman's nightmare. This is derived from ancient stories in which a 'mara' was a spirit in northern mythology that came to sleeping women, and either suffocated or molested them. There are other stories involving this character in which women are impregnated by these creatures, and then give birth to abnormal, half-human beings. The second interpretation would be that the imp is actually the inner evil, or possibly the id, of the woman being expressed. Since the romantic era dealt with the idea of accepting the inner truth of one's nature, this interpretation is highly plausible.