<img src="/images/welcome.gif" width="500" height="62"><br><b><i><big><big>To Reef Central</b></i></big></big>
Does not appear to be any of the hosting species.
Need a better picture of the tentacle branching, column, and maybe mouth to narrow it down, but at that size a precise species ID is going to be tough.
Have you tried to feed it yet?
Any idea of source?