Bristleworm. Some remove them because they can overpopulate a tank careful removing them DO NOT touch them their bristles will harm you. Others leave them as they are harmless part of the clean up crew.
Thank you. Didn't know they were pink n brown in color. Guess I need to really get that yellow coris wrasse. I am always scared I'm gonna end up with a bobbit worm.
I freshwater dipped a piece of live rock the size of a quarter recently.. . appeared to be a very solid rock. a tiny bristleworm came out of the rockwork. if you have any liverock at all they are in your tank.