yes, better pic indicates it is a Majano anemone (Anemonia cf. majano). Although considered a pest because they spread rapidly by fission and outcompete corals for space (and also sting corals) they are very beautiful. Under certian situations (in reef systems with good water quality and good nutrient export systems, they do not tend to become a problem as they generaly remain as an isolated polyp without multiplying.
If you like it, keep it and watch it for issues (ie. rapid multiplication). If you want to get rid of it, I am sure that there are hobbiest on this forum that would be more than happy to give it a home in a fish only aquarium where it will not causse issues.
P.S. they look great when they host sexy shrimp or anemone crabs.