The Yoshimoto Cube
This is a pretty amazing folding transformation of a 2-unit cube into a pair of stellated rhombic dodecahedra. You can buy the (fairly pricey) toy version pictured above from the Museum of Modern Art. It is also possible to make your own, from paper, by following the instructions in the video below. It is, reportedly, a very rewarding if time-consuming process. You can download the pattern here.