I have a worm in my tank that came in with a piece of live rock with maidens hair on it. I am unable to get a picture because it is very thin, about the thickness of a strand of maidens hair. It curls up over and over on itself so I can't tell exactly how long it is but saw it tonight stretch over to another piece of rock a good 3". It has alternating black and white serrations with each section several mm long. Gives me weebie jeebies like some kind of snake. Any idea what it might be?