Dream about dark snake is a sign for your lack of privacy. You are feeling rejected by society. You are harboring some inner guilt that you are harboring. This dream refers to a kind of cleansing or ridding of bad karma. You need to show better restraint in holding back your anger.
Dark snake dream signals someone who is on the edge or on the cusp of something new. You are trying to understand your Self and find out who you are. Your mind is too cluttered. This states instability flightiness or activity. You need to use your position and leverage to get what you want.
If you dreamt about dark snake:
A flaw in your current relationship, which up until now has remained hidden, may be suddenly revealed today. The question is, what are you now going to do about it? You can choose to ignore it, hoping that if you keep that subject at bay it will eventually vanish, or you can begin to be responsible at least for your actions and start to do something positive.