The Fractal Puzzle is a very challenging, very confusing laser cut puzzle that is built from the self-similar fractal Gosper Curve. It can be cut from cardboard, acrylic or wood, although the corrugations make the cardboard somewhat difficult to take it apart. Since the curve has similar repetitions, the puzzle is full of "garden paths" that seem like they are almost right.
If you cut two puzzles from different acrylics, you can merge them to make two very striking bi-color puzzles.
More info: https://trmm.net/Fractal_Puzzle