It is used to poison the fish food and the piranhas found in the fountain on the grounds of Draynor Manor during the Ernest the Chicken quest. It is also used to poison the Carnillean household's food in Hazeel Cult.
If players attempt to use it to poison the sheep Sheep Herder instead of the Sheep feed, a message will appear saying: "The sheep isn't going to drink the poison from the bottle. Perhaps you should try feeding it something else more appropriate."
Kebabs could be poisoned and then traded. This could be used to kill other players as the kebabs looked the same and had the same examine text. This feature was removed as it was considered a form of scamming.