Herbalism Profession
There will be new, rare herbs only found in Outland, and some will bestow (or inflict) strange effects on the herbalism profession who picks them. Also, plant beasts roam the shattered lands beyond the Dark Portal, and their alien forms hold rare ingredients only harvestable by herbalism Profession. You will "skin" the plant beasts using your herbalism profession skill to acquire the ingredients they are carrying, much like skinners harvest beast hides for leather.

Herbalism Profession