I want to make clear that none of the puzzles on this page are boxes. By no stretch of the imagination could they be described as 'cubes'. Ask any mathematician. That's not a cube, he'll tell you.

This octahedron isn't even remotely like a cube. It's similar to a solid puzzle invented by Josef Trajber. An image of the puzzle.
Similar to the above, here is a smaller octahedron. An image of the puzzle.