It's not a brittle star. It has a specific name. I have a link on my home pc that has a pic of one of these and I will look for it when I get home from work. Possibly a Sea Pen but that is a wild guess from memory.
I know I've seen that ID'd before...some type of sensile filter feeder but a name escapes me...where is the master bug man when you really need him.
Bang would be the one to positive ID it...but if memory serves me right it is harmless and should pose no problems. Just a filter feeder.
Man I wish my memory on this stuff would work...thats what happens when ya get old!!
You're on the right track attml. Its a Feather Hydriod, probably Gymnangium longicauda. I think they are harmless to your reef, but will sting your bare skin when they get big enough. (12 inch max I think, but doubt they will get that big in your aquarium. Enjoy the hitchhiker IMO.
Nice critter. I'll take it off your hands. Looks like a fliter feeder. I saw a stripped tentacle the other day in my 20 that was most definitely a worm but what it would do is open up a crown at its end and seem to rake the rock. Very cool....