Found this in my liverock.

[speddlysmitt]

Found picture on another site but I am looking for more detail since I found it in my tank.
What is this,
It's skin is smooth and it is black on white.
It lives on a rock ledge/mini cave and the it moves out and where it's head should be, some white tenticle things come out and then retract.
The worm is in the middle of the pic

Thanks

 

[speddlysmitt]

It's head looks like this.

Could this be an sipunculid

 

[fordp]

Yep it's a peanut worm.. They look like accordions when they retreat back in the rock. I have a few in my tank. Some are striped, most appear to be solid brown though.

 

[mouserusker]

Are peanut worms annelids?