Airborne Snapshot

From Halopedia, the Halo wiki

Halo 5: Guardians Airborne Snapshot

Airborne Snapshot is awarded in Halo 5: Guardians for killing an enemy while in the air not being zoomed in. This can be accomplished with a Sniper Rifle, Beam Rifle, or a Binary Rifle. It is represented by a Sniper Kill medal with a skull instead of a crosshair.