This tiny snail was discovered in the overflow box of my 280g reef tank. It is called a Peppermint Snail. Its shell looks glossy, and it is a relatively mobile creature. When I saw it, I dashed off to get my camera and had some trouble locating it again in an area that is only 12" x 6". It is probably 3/8" long and 1/8" wide, and projects a snout that is tough to see in this image. Reef-safe.