To reach him: go down the ladder South of the atoll and follow the long dangerous maze to the end. Use the talisman and bones on Zooknock and you will obtain a greegree.
The kinds of bones used will create different types of greegree:
Monkey bones: Monkey greegree (Karamjan)
Small ninja monkey bones: Ninja monkey greegree (small)
Medium ninja monkey bones: Ninja monkey greegree (medium)
Large zombie monkey bones: Zombie monkey greegree (large)
Small zombie monkey bones: Zombie monkey greegree (small)
Bearded gorilla bones: Gorilla greegree (bearded)
Gorilla bones: Gorilla greegree
Monkey skull: Gorilla greegree (blue)
When the greegree is created the talisman is consumed, however, a new one can be obtained to create any of the other greegree.