Hairy creature!

[mcgyvr]

Whatever it is its neat... and I would certainly recommend against the typical knee jerk reaction to remove it first and ask questions later..
I would leave it in my tank as its likely harmless filter feeder of some sort.

 

[reef cuber]

zooming in on an already blury photo doesn't make it easier to see. what does it do? Is it always out? Does it pull in when disturbed? Does it go in and out like it's feeding? Does it move around in the tank?