carpet anemones......some witness them eating small fishes...so if you intend to keep neon goby , etc, not advisable. Can get those n. snail, scarlet hermit, gobies, shrimp(when light out, it is likely to move round your tank in search for food), etc. Those big hermit(electric blue leg, etc) will eat your snail and maybe your coraline algae(for some type) and big turbo snail(topple your stuff) ...etc..you may wish to avoid.....