Need help with one client order

[Adept]

Hi there :) Don't seem to know how to complete this one, can anyone help? Thanks.

http://i.imgur.com/rHLot.jpg

[CyberNei]

You need to farm 20 items from lv 21 Garongos (green big dunnowhattocallthatthinglike mobs that likes to role play wheels). Need to go forest mission on hard i suppose.

[Adept]

Oh okay, thanks for the help. That's going to be annoying since they rarely spawn :/