During my recent Gears of War 3 insanity playthrough (yes I like doing this to myself) I also completed the “secret achievement” *SPOILER FREE* during the mission in Char (Act4 Chapter1), don’t touch or shoot any of the ash statues and when you reach “the tower” there is a stranded who will open a gate to a room full of weapons with you. When in this room i spotted a giant chicken with a red pirate hat on.. so what do I do? Shoot it. It then disappeared in a semi suspicious manner. Once you are on the “other tower” after first seeing formers on the roof near the empty swimming pool (Act4 Chapter3). Conveniently also it is very close to where the “Fuel Order” collectible is found. There is a pile of boxes and barrels place precariously on the edge of the roof with an ammo box on top. If you kick this pile it wobbles and falls off the roof. No ammo! However give it about 2 seconds and Marcus (only tried it on my own so not sure if they all speak) will say something and along comes.. a surprise to say the least! The chicken in a pirate hat was back! On a flying ammo box with wings that was dropping boomshots out of it. However if you pick one up you will find that it is actually a “Cluck Shot” 4 are dropped so you can pick up 2 for full ammo or have 1 each if playing in coop. These are essentially a normal boomshot however they fire highly explosive chickens and make a hilarious noise to boot!
Oh but sadly it doesn’t use normal bootshot ammo so once it’s gone it’s gone!
Hope you enjoy,
Excellent collectibles guide here: http://mycheats.1up.com/view/section/3173372/31794/gears_of_war_3/xbox_360