without a pic, you can't be sure just by saying that it is a starfish...there are several different types of starfish that hitch on LR (search for asterina star fish...they are VERY common hitch hikers). Same thing with the worm...could be a bristleworm, which help to get rid of leftovers in the tank, or it could be something that could be potentially dangerous to your tank...
either get a picture or give a better description (in the meantime, look up asterina stars and bristleworms...to avoid having to take pictures, as the worm will most likely only come out at feeding time/when the lights go out).