Soldier Orbyu:
Really? Thank you.
If you hunt Rok and open its stomach, you will find undigested remains. The same is true of the Mutant Birds and Dra Hawks, although you'll find fewer remains in them.
Bring me Swallowed Skulls as evidence, as well as Swallowed Sternums and Swallowed Bones. We will reward you for your efforts -- especially for the skulls you bring back.
One more thing: Rok fears the Dark Black Dragon's followers. That's why it emerges only when the Seed of Infinity is stabilized. That means Rok can only be hunted when the Seed is occupied. Remember that!
Good luck and good hunting.