Gnomus at Wildhammer Stronghold in Shadowmoon Valley wants you to recover 1 Overdeveloped Felfire Gizzard.
I remember seeing larger diemetradons east of the Hand of Gul'dan, near the lava flows around the Ruins of Baa'ri. What I want you to get for me now is one overdeveloped felfire gizzard from the beasts around that area. You might have to kill several to find a gizzard like the one I described. Keep at it! One of them is bound to have my next meal.