Brown worm with feathers?

[Ben 4]

I recently purchased some macroalgae and I discovered a small, @1" long brown grub-like critter that has what look like feather-duster type worms sticking out at one end. The "feathers" are black and yellow colored. The organism seems to squirm when you pick it up. The only thing close to it in appearance in my books is a Medusa worm but I don't think that is what it is. Any ideas? Thanks.

 

[jchonline]

Run for your life!! It is a mutant Bristleworm!! Will probably eat glass too.

J/K. I have no idea what little critter you have there.