help with id

[tsw5013]

found this in my sand. removed it from the tank. it comes out the end and almost doubles in size. moves down into the sand. i did loss a feather duster some time back. other than that have not lost anything else in the tank. help dont want to put it back until i know what it is.

 

[MarkShimala]

I would say ribbon worm. I read that there are over 1000 kinds of them. I also read that they can latch on fish and that cant be good. If it was in my tank.....I would take a lot of pictures snd then maybe toss it in a container and see if your LFS can positively identify it. I also read that if they break in half they will both survive.....and, they can split themselves also.