white paintbrush looking thing with yellow bristles popped out of rock, any ideas?

[gsxrguru2]

I don't have my digi camera handy, but the description of this thing is pretty straight forward: It looks like a paintbrush. The base of it is white and extends from the rock about 1/2" and then there are these yellow bristles that extend out almost like a fan. It wasn't there 24 hours ago when I looked in the tank last so whatever it is, it's a very fast grower. Its also growing on a rock that I moved to my qt tank a few days ago. Anybody have an idea of what this could be?

[gsxrguru2]

Ha! Well, I found out what it was... one of my fish died and buried itself in a hole in the rock a good inch or two. Oh well, at least the others seem perfectly fine and thank God for liveaquaria's gurantee on livestock.