Xenia corals are soft marine corals known for the unique pulsing motion of their polyps. They are colonial animals with multiple individual polyps attached to a piece of solid substrate. Most species have unbranched stalks, which are short, thick and smooth, from which the polyps grow. They are typically cream, white brown, ivory or light green. Xenia are a good coral for beginners; however, they do grow quickly and can take over a tank if not controlled properly.