A good place to hunt Kilif Zefirs is in the Mountain Sewer. To get there run southwest from Tou-Tou to 29.8S, 93.9E or take the Mountain Sewer portal in the west wing of the Facility Hub (hub portal is 30+).
Hadiya bint Anan tells you, "So, you wish to prove your hunting prowess? Well then. Track down and slay 35 of the cunning Kilif Zefir for me, and I will reward you appropriately."
Hadiya bint Anan gives you Kilif Zefir Sites.
Hadiya bint Anan tells you, "Excellent work, friend! You have slain many of the cunning creatures! Allow me to reward you!"
You've earned 150,000 experience.
You have been given the title Zefir Zapper
Hadiya bint Anan tells you, "Ah, friend, it is good to see you back again! But we must take care not to wipe out all of the Kilif Zefir, yes? Give them a couple of weeks to replenish their numbers, then come see me again."