The concept for this puzzle is based on a tessellation by an artist named M. C. Escher.  This is one of his better known sketches.  To tessellate means:  to form into small squares or blocks; form or arrange in a checkered or mosaic pattern.  This design is based 120 degree rotational symmetry.  The outline of the lizard is made up of one line, duplicated, rotated and connected to the end of the previous line 3 times, and the tiles can fit 4 different ways.
     Some interesting math fun:  each tile is rotated 120 degrees from its neighbor. 3 tiles fit together 4 different ways.  It takes 6 tiles to surround 1, for a total of 7. 12 surround that for a total of 19 tiles which make a layer. It takes 18, or 1 layer minus a tile, to surround a layer.

     The framework for the smaller hexagon set (left) is 9" in Diameter by 1" Thick.  Each tile in this puzzle is approximately 2" x 2" by 5/16" thick.
     The tiles in the larger puzzle set (center) are approximately 3" x 3", with a keeper ring that is a mock up of the next surrounding circle out.  The tiles can be placed all around the ring as you can see in the image at right.