What does it mean to dream of a scary little girl with long black hair?

This image of a "scary little girl" in your dream might be drawn from any number of Horror films or Gothic novels. Samara Morgan, for instance, could be whom you are dreaming about, in a part where her blonde hair is darkened. The point is that this dream girl is only an image that represents something that frightens you. The actual interpretation of the dream depends on other factors, such as whether or not you are a young girl or adult woman yourself, whether you have an actual relationship, past or present, with a dark-haired girl, whether you play Video Games in which this avatar confronts your own avatar, and countless other possibilities. The important thing to know is that this little girl is a symbol that represents something in your own emotional experience.