I 3rd that.. Manjano.. really cool looking for being a pest but can quickly get out of control in a tank just like aiptasia. It should probably be removed if you plan on having other corals, just like that one aiptasia I also see at the top of the picture on the same rock. They have the potential of stinging your zoas and wiping them out. From the pictures, it seems as though both pest anemones are doing just that, stinging the zoas by the looks of them.