Ok, some new creatures have appeared tonight in my reef. I just posted the snail I found tonight and I just found this thing in my overflow. The pictures aren't really that great but it was the best I could do with the angle I had to shoot them from. This thing is about a 1/2" or so and moves pretty damn fast for a snail/slug. I thought it didn't have a hard shell at first, but I think it might. If it is a shell on top it is black with tan spots almost hairy or spiked like a porcupine. It also looks rough like an oyster. It has 2 eyes and a snail looking mouth and he was munching away at the detritus at the bottom of the overflow. I am guessing that he and the snail were in the tank for a while and are reef safe because the only thing I added recently was a small frag and some sea lettuce and they are to big for me not to notice them. Any idea what this is?