This is the worms head and it does use this end to attach to substrate.I found this worm in my 3000 gallon pond. I thought is was a flat worm but after photographing and enhancing with PS it appears to be segmented. I suspect a leach but have no idea what it might be eating. I just have goldfish and mosquito fish in the pond.
Long worms wriggling in the sand/silt flats at low tide.