This part of the forum is always my favorite cause you never know what you'll find in your tank!
I've got some little guys in my tank.. started with only a few but they seem to have spread quite a bit over the last year or so. In my early stages in the hobby I had thought they were some sort of tube worm or feather duster or something. But now that I'm a more experienced hobbiest I believe them to be some type of anemone.
I'm pretty sure its not aptasia because they look a lot different and seem to not grow very large or be harmful in any way.
They remain fairly small so I cant seem to get a very good picture but the best way I can describe them is mostly clear in color but they have white dots at the end of their tentacles.
The closest picture I can find is this:
http://shivelygallery.com/thumbs/PR2...rallimorph.jpg
But its really not very close.. they are significantly smaller with no real visible color