Soloman,

If you really want to 'duplicate' that fly with something that would actually make noise in the water (real snake rattles won't), it can be done and you can keep the 'look'.

Melt a ball on the end of some heavy mono, thread on some glass beads in a proper color and ascending sizes, then tie the mono to the hook, leaving enough 'slack' between the beads so that they will click together a bit.

If you can find a bead store, they actually make glass beads that imitate snake rattles....or, if you know a glass beadmaker, they aren't hard to create with basic skills....

Cool fly.

Buddy