Here is a Moi model of the foxagon puzzle.
Extrusion along the z axis is just to provide top and bottom faces of different colors.

The foxagon pdf was opened in Moi.
http://userpages.monmouth.com/~colonel/

Instructions:
Fit the pieces together to form a regular
hexagon so that no adjacent triangles
appear with the same color.

- Brian

Apparently this is not a polyomino.