Herbi Flax was a resident of Mort'ton, a small human settlement in southern Morytania. Flax lived during the town's final days in the recent Fifth Age, when an infectious plague from the Sanguinesti region wiped out the town's populace, putting them in a zombie-like state.
Herbi Flax was amongst the first to research a cure for the plague, successfully creating multiple serums that could weaken or temporarily cure the plague. He also heard the legends of the power of the Flamtaer Temple, which he was very sceptical about, even though its power could be used to fight against the virus. Ultimately, though, his efforts failed, descending into madness at the hands of the plague and never finding an effective cure. His assistant Liornish Stemplehair also fell victim to the disease.
The Diary of Herbi Flax can still be found in his ruined home in central Mort'ton. It contains information regarding the plague, which may be helpful during the Shades of Mort'ton quest.
- His name, Herbi Flax, seems to be a reference to the work he did with Herblore.