G'nathus is an Elite mob with 43 million HP that swims around the Northern part of the Island Shanze'Dao off the coast of Townlong Steppes. He drops this pet.
We tried various set ups to down this mob, (paladin tank, enhance shaman for frost shock) Finally realising I could just use Hibernate and Starfire/Wrath spam him to death, took 34 minutes to solo him this way.
I would say you deffo need to be able to kite him, he hits too hard otherwise. Goodluck:)