Plating Hydnophora, highly aggressive. The coral is capable of sending out 5 inch stinging mesenterial filament with the right current. One of my favorite corals but it needs a lot of real estate.
Tahoe61 has it right. They are listed as SPS but in all other ways a LPS in nature. Just watch them eat. They are the acan echinata of the SPS world very aggressive.
