Stay airborne by swinging from one grappling hook point to another

Gather information using a scout

Perform 5 assassinations in a row without being noticed or entering combat

Perform your first assassination

Attain 100% Game Completion statistic in Undead Nightmare.

Find and break a unicorn.

Attain Rank 5 in all Undead Nightmare Challenges.

Complete "On a Pale Horse".

Destroy 50 Aerial Scorestreaks with Launchers in Multiplayer

Shoot an enemy in a sensitive spot.

Complete "Cure For Most of What Ails You" and "Get Back in that Hole, Partner" Survivor Missions.

Complete the Training Course in Multiplayer

Complete the Campaign on any difficulty