Wunderlich's jumping octahedron is a polyhedron with two stable configurations. The fun part about this polyhedron is that with a little twist of the top surface, the model snaps into the other position. Hence the word "jumping" in its name. This polyhedron is not truly flexible in the way that Steffen's flexible polyhedron. is. The faces deform a little as you move between states, but it is this deformation that gives it the spring that drives this behavior.