Speak with Gryphon Master Talonaxe.
Sharpbeak is held in a cage, high on a cliff at the top of Jintha'Alor in the Hinterlands. The key to this cage is possessed by the high priestess of the Vilebranch trolls, Vile Priestess Hexx.
There. I have done my part. I bid you fortune on your quest, [player].