These are adorable colonial encrusting polyp corals I would recommend to any beginner. I got mine mail-order from a private cultivator, and they have never given me problems; they are not highly aggressive and stay to an area, but at the same time also very easy to propagate. They are also tolerant of all sorts of lighting and water conditions. There are also numerous other color varieties of different zoanthusspecies. I also have some green sea mat colonies that grow just as fast and are just as hardy.