Wulgrig

Wulgrig is a Tome of Knowledge Bestiary entry for Zombie.

Instructions: Order & Destruction

Interact with 'Pile of Rocks' in Cinderfall at 44k 2.5k inside 'Palik Tunnels' (entrance at 47.7k 7k). To reach it, go north at the first junction inside Palik Tunnels, descend the ramp, and go left. You will find it in the first room behind a column on the left.
Interacting with this 'Pile of Rocks' will make spawn 'Wulgrig', a level 36 zombie. Kill him for the unlock.