Reflective Scale

Source
This item drops from the following Hatecoil naga in Azsuna:
 * Hatecoil Spitespeaker
 * Hatecoil Raider
 * Hatecoil Riptail
 * Hatecoil Stormcaller
 * Naga Brute

As a quest objective
This item is an objective of A New Invention.