Bobble Octopus

This is fairly easy to assemble. Pretty much you just have to glue one of the pen spring holders to the spring, and on to the body. Then you glue the pen spring with the holder attached to the inside of the head. Lastly you just have to glue the bottom half to the top half. For printing the spring, add a brim and slow the print speed down a little more than you usually have it. With these settings, you should get a good spring, I would recommend the pen spring just because it is more durable and easier to print.