This was on a favia rock I picked up this week. It's tube is hard and I'm concerned because the feather dusters I had didn't have a hard tube.
It seems to have a head but I'm not sure and after the first part extends a bit then you see a small feather duster looking thing come out around it. These aren't great pics but I'll work on it after I pound my face with turkey. Haha. Happy Thanksgiving!