Bristleworm
They just eat a lot of leftovers and waste. If you do take it out to put in in the 75gal, don't touch the bristles. They can swell your fingers so that you can't move them. Use a fish trap, put in some food with garlic and put where you see him. He'll go in after the food. Use gloves if you do it by hand.[I have several in my school tank. The kids think that they are cool.
Regarding large size....I once saw a picture of a large one that was taken out of a big tank and it was laid on the ground outside and went the length of a volkswagen beetle.
Now that was a large one.
QUOTE=KenG;380091]I recently added a pistol shrimp/goby pair to my 10gal nano and I noticed a large bristle worm which had come in with my live rock. Should I be at all concerned about these together? If so, the bristle worm could find a home in my 75gal. If no concerns I am sure he will be king of the nano at clean up time.[/QUOTE]