Take the Shrunken Head to Neeru Fireblade in Orgrimmar.
Neeru Fireblade in Orgrimmar has what I need to get started here! He has mixed up a concoction that I need for my... well, you'll see.
Off with you now -- to Orgrimmar. Here, take this with you. It's a shrunken head that I promised Neeru in exchange for the herbs. It's the head of some poor dwarf I ventured across in the forest. I'm sure Neeru will be pleased.
You'll find Neeru in the Cleft of Shadow.