Rubikâs Cube Barrel/Octagonal Puzzle
I bought one of these on eBay a few years ago. It's SO pretty and seems like it ought to solve just like the 3x3... after all, it IS a 3x3 with the corners cut off... right? WRONG! When you're looking for a break from the structure of the cube, this one's quite a trip. It makes some funky (and infuriating) shapes! Good luck!