When you arrive at the Graveyard in Inkana Canyon, you will see a giat skull at the north arch. You must play the Sonta of Awakening to awake him. He will rise and start hobbling off. Normally you would have to chase him through all of the firewalls, but you can go through the first firewall, turn around, (if you have the grappling hook) grapple to the chest at the top, jump to the opposite side, fight the guy, and save yourself all of the trouble.