The Yak might be an intimidating beast, but this puzzle could prove to be a tough nut to crack as well. Made from resistant 3mm nickel plated wire and brass for the diamond shapes, The Yak Puzzle requires you to remove the handle from the frame and then put it back to its starting position. A very challenging puzzle from the designer Dick Hess, who has created other interesting wire puzzles, like the Brontosaurus or The Whale.