This is Mike, the Back Scratcher.  I've been validating this design for going on six years now, and let me tell you it's a winner.  Rigorous testing.

There isn't much to Mike - I 3D printed a little scratchy bit in either light pink or brown and stuck it on a ½" dowel.  The points are actually pretty sharp, which some people are really into (you could always file them down slightly, but remember you can't ever make them pointier).  

I print these vertically at a 22* orientation with a small brim and organic supports - works a treat!