I have had my live rock for about 16 months now. I have never seen this creature before. The best description I can give of it is that it looks like a thin clam mantle (I know it's not a clam) that retracts when it gets light on it. I have a poor quality pic. I know I've seen pics of these on the boards here, but I can't remember what it's called. I've isolated the rock from others, and could try to get a better pic, but I'm not promising anything. I know someone will refresh me on what this is.
