Izila Masks
Izila Masks are masks the Izila have placed all around their territory to give them blessings. You don't "collect" it like the other collectibles. You destroy them by shooting them or even if you manage to hit it with melee. The tooltip says destroying these lowers the Izila morale. However this isn't the case and does nothing to the Izila you face.
You can find it on the map ONLY in Izila territory. It is an inverted triangle that seems like a face (of course. its a mask).
TIP: To find collectibles easier, go to the map, press D-Pad Up or D-Pad Down to open up the filter menu. Scroll down to highlight Collectibles to highlight only collectibles from all across the map.
IMPORTANT: Collecting / Destroying Izila Masks only gives some EXP and nothing else. The only achievement that is tied to collectibles is obtaining any combination of 80 collectibles. By following the Tips we have told you, you don't have to collect / destroy all the Izila Masks to get max level.