From the Harbinger quest introduced in the Into the Darkness event.

Insidious Monouga Idol
Value: 200
10 Burden Units


Notes

You give Ivory Crafter Insidious Monouga Idol.
Ivory Crafter tells you, "This is an excellent find. My friend is working on a collection and has given me an exclusive special offer. You qualify for the special collector's edition Tremendous Monouga Pack Doll. Supplies are limited, so only one per person, per month."
Ivory Crafter gives you Tremendous Monouga Pack Doll.