Definately looks like a peanut worm... was amazed at the first one I found and how quickly it can retract when light is shined on it. Started using a red LED light at night to see what other creatures I could find. (I now know I have a lot of peanut worms - and by the sounds of it have many more I have not seen
Anyways nice photo of the peanut worm above... have you noticed any sort of darker banding on it when it is outstretched? It seems the ones I have all have darker banding when outstretched.