Capture the spirits of 3 screechers in Feralas, then return to Yeh'kinya in Steamwheedle Port.
3x Screecher Spirits Collected
I seek the spirits of the vale screechers of Feralas. They are the cousins of an old, old god, and their spirits are linked to him.
Take this bramble wand and go to Feralas. Find and defeat vale screechers in southern and central Feralas, then wave my bramble over their fallen bodies. This will coax their spirit to reveal itself. Touch the spirit and collect its essence.
Return to me with my bramble and with the collected essence, and I will tell you more of the old god of which I spoke.