A Boom shot that fires exploding Chickens .
1. To start off, you’re going to need to play through Act 4 Chapter 1 on Insane. So this means you either have to beat the game once already, or you’ll need to play coop with someone who has beaten the game once.
2. Go through Act 1 without touching any of the ash bodies. Doing so will get you the secret “Respect For the Dead” Achievement once you arrive at Griffin’s Hideout and enter his secret weapon stash. More importantly though, it will give you access to this little chicken to the right with a pirate hat. Press X to interact with the chicken to cause it to explode, as if to officially kick off our easter egg hunt.
3. Now, play through Act 4 Chapter 2 like normal. Just make sure that you find two special ammo boxes that fall off a cliff as you approach them. The first one can be found at the start of the act on top of a car. The second can be found at the end of a railroad track in the underground section where you’re attacked by Polyps.
4. Now continue playing as normal until you reach Act 4 Chapter 3. After you head past the lift and go through the barbed wire, you’ll come to a fight with a bunch of Formers. Make sure to take them all out and then look for a stack of objects with another ammo box on top. Kick the stack to cause the ammo box to fall. Wait for a second and you’ll spot your “air support.” One specially made Cluckshot for every member of your party!