Dreaming of a mean person represents the meanness within yourself. All dream characters represent an aspect of you (since you created that character 100% in your own mind), so this dream character represents that part of yourself that is mean to others. Examine the behavior of the mean person and his/her interactions with you and the other dream characters for greater insights into how this part of you treats others. Particularly pay attention to the way you felt in the dream in relation to the mean person. This empathy is showing you the way others feel when you act mean to them.