Gnomish Battle Chicken is used to obtain an attack speed buff for 2 minutes, helping you boost your damage during boss fights. To get it, you need Engineering leveled to 200+.
Start by picking up the Gnome Engineering quest in Undercity from Graham Van Talen. His coordinates are 75.8, 72.6.
Next, travel to Booty Bay and speak with Oglethorpe Obnoticus. His coordinates are 28.4, 76.3. Turn in the quest and pick up the next one, called The Pledge of Secrecy. Use the quest item, hand it back to Oglethorpe Obnoticus, and then accept the final quest in the chain: Show Your Work.
To complete this quest, you will need the following materials:
6 Mithril Tube
1 Accurate Scope
2 Advanced Target Dummy
Bring all the required parts to Oglethorpe Obnoticus. After completing the quest, you will unlock the ability to learn Gnomish Engineering recipes and craft fantastic, yet unreliable, gnomish devices.
Finally, learn the Gnomish Battle Chicken recipe from him. Now you can craft your own Battle Chicken and use it to increase your DPS in raids.
And yes, if you ever need to drop Gnomish Engineering and switch to Goblin Engineering, you can do it in Tanaris. Near Narain Soothfancy, at coordinates 65.3, 18.5, there is a book lying on the table. Click the book, renounce Gnomish Engineering, and then learn Goblin Engineering from her.
