Cluckshot

In Act 4, Chapter 1, avoid the ash bodies until you reach Griffin's first tower. A room will open containing Torque Bows, Boomshots, and a chicken statue wearing a pirate hat. Press (X) on the statue to make it explode in flowers.

In Chapter 2, near the beginning, you will see an ammo box on top of a car. Go near the car to make the ammo box fall over the edge.

Still in Chapter 2, before the big fight in front of the second tower, look left on the broken train tracks for another ammo box. Go to this ammo box to make it fall over.

In Chapter 3, clear out the wave of Lambent Humans outside. Then, go around until you see another ammo box on top of stacked barrels. Kick the barrels over to make the ammo box fall. The pirate chicken from earlier will then carry up an ammo box shaped like a Chicken. After a few seconds, it will dispense 4 'cluckshots'.