Gears of War 3 Easter Egg - Flower-Power Lambent Chicken

On the first level of the campaign, at the part with the pumpkins, kill all the lambent grubs and then you should be able to see four pipes, two on the left and two on the right. Keep shooting down each one until Marcus says "Hellooooo." Once you've finished the last pipe a chicken should pop out. Keep shooting the chicken but not with active reload as you will kill it too soon. If you shoot it long enough it'll grow huge and lambent and start breathing fire on you. When you kill it lots of flowers will pop into the air.