I have three of these little "critters" that came in on the same live rock. They started out as really small and I thought they were some type of majano. As they got bigger, however, they look more like coral. To my eye, they look most like those purple and green diaseris plate coral, fungia, or something similar. Does anyone else have a better guess? I can't tell for sure whether or not there is a skeleton but they do not close up like an anemone. Unfortunately, they're relatively inaccessible in the tank.