The four different pieces of this puzzle are actually the borders of a self-avoiding plane-filling curve-set which live on the square grid. We call those objects monstercurves.
The non-trivial self-similarity of the curve-set provides four different puzzle challenges, as shown in the pictures. Each puzzle piece can be build in a “big version” by assembling the pieces.
Those big pieces can also be assembled into patterns or abstract looking forms we call tiles for even more puzzling fun. Those tiles do indeed tile the plane just by translation.
The puzzle is made of MDF. You can paint the pieces of the puzzle yourself if you like!