Circa 1980's.
(plastic, 4 inches as assembled above)

A sequence of linked plastic pieces that can an be folded into fun shapes. The "solved" position is a 3D diamond shape shown above that fits into the plastic ball in which the puzzle was sold.

Further Reading
Rubik's Snake Booklet, from: http://www.rubiks.com/World/~/media/Files/hint_snake.ashx
McFArren's Page, from: http://www.geocities.com/abcmcfarren/math/snake2d.htm
McFarren's 3D Page, from: http://www.geocities.com/abcmcfarren/math/snake3d.htm
Wikipedia Page, from: http://en.wikipedia.org/wiki/Rubik's_Snake