Eight-Pointed Snap Star

This 3-D star can 'snap' onto a string.  Make several from various colors of foil paper and hang them from a string. 
Here is a front view, showing the 'open' position, where the back is loose, allowing a string to be inserted.  Pushing (snapping) the center forward tightens the back layers against the string.
Here is a side view (bottom-up), showing the 3D shape.
Here is a back view.  Notice that some parts are curved.