Go to Saldean's Farm in Westfall and find a chicken. Select it and type /chicken into the chat window. Note: Setting up a macro for this will make it go a lot quicker. Do this until "Chicken looks at you quizzically. Maybe you should inspect it?" appears in the chat window. It requires a lot of tries to do this; patience is required. If done correctly, right-clicking over the chicken should open a quest window. Accept it and purchase the Special Chicken Feed from Farmer Saldean. Return to the chicken, select it, then type /cheer into the chat window. Right click the chicken and complete the quest. If everything is done correctly, the chicken will now lay an egg. This egg is your new pet, a Prairie Chicken.

Although the quest to obtain the prairie chicken is Alliance only it is possible to get the chicken as a Horde member. Have a friend on an Alliance account do the quest and allow you to pick up the egg from the ground. Alternately, steal the egg when an Alliance member finishes the quest and the chicken lays its egg. This is an very rare pet in the Horde.