Wunderlich's jumping octahedra
The three dashed diagonals show "valley folds".
This net can lead to two distinct polyhedra which derive from a triangular prism by about 15° and 50° twists.
If you build a model out of thin card, you find that the two positions are interchangeable: a light pressure and the model jumps from one position to the other. To build your own model you may download and print the net (PDF file).
||Polyhedra by Peter R. Cromwell (Cambridge University Press - 1997) pages 222-223 |