black snake
gaydemon > dictionary > black snake
black snake | Gay slang or terminology for a man's penis, who is of dark skin color. In short a black man's penis.
Meaning
Rightly or wrongly, many associate Black males with having larger than average penises.
The connection of a large snake to describe the appendage is quite normal, when talking about long dicks.
Adding black to the common term, snake, is to denote the skin color of the owner.