This quest is no longer active ingame. The only current possible way to obtain Mango Water is through Event Giftboxes.
In this quest you are asked to find the Legendary Herb(Mandragora).
Where to start: find Pafris who is standing next to a tree and a post sign at the bottom of Woody-Weedy Forest or Woody-Wordy Forest. (Exact Coordinates are 1934,2802). He will explain that he has been hearing about a herb called Mandragora and it's somewhere inside the Mushroom Spore cave (3408,1161) located in the Mushroom Marshland. The herb screams when being pulled killing the person so he gives you Earplugs to pull it (You cannot pull out the herb without earplugs). The Mandragora is located at the end of the Mushroom Spore so be careful as in the area it is located, the herb is surrounded by Mushroom Flower(s) which can do a lot of damage when all attack you at once if you are a somewhat low level. When you pull the herb walk back to Pafris and he will give you Mango Water. You can only hold one Earplug at a time so you can only get mango waters one at a time. Earplugs are soulbound and cannot be worn.
A potion with the fragrance and tastes of a mango.
How to Obtain:
Trade Pafris, Mandragora Herb (1) (Pafris' Search for Legendary Herb)
Increase critical by 4 for 20 minutes
Cool time 60 seconds