I checked the site you posted. I can't tell for sure. I found a picture in one of my books and it looks a little like the Triffid Anemone
I sure hope not. Lists it as wolf in sheep's clothing. It looks as if there is another one showing up on the other side of the rock. It isn't exactly the color of the one in the book. The one in my tank is a little more on the pink/beige side. I don't know whether to be happy because it's something I want or sad because it's something I don't want.