For a list of usable potions, see Potions
The potion is a quest item that appears in the Watchtower quest. It is used to kill Ogre shaman that live in the caves below Gu'Tanoth.
To make the potion the player must mix guam leaf, jangerberries and ground bat bones bones into a vial of water. This specific order must be followed or the potion will explode, damaging the player. Then, it needs to be enchanted by the Watchtower Wizard, to turn it into a Magic ogre potion.