I looked into my tank this morning and thought I had a little sprout of GSP coming out of a random rock, but then I looked closer and noticed it was slowly crawling over the rock. I did a quick internet search and I think it's a nudibranch. It's appearance just so happens to coincide with one of my zoanthid colonies shutting up tight. After great pains, and a plastic spoon taped to the end of a wooden dowel, I managed to get him out of the tank.
He's a bad guy, yes?
He's a bad guy, yes?