Ffyrnig Tonic

A huge wooden sphere, about four feet across and weighing hundreds of pounds, lies half-buried and overgrown, strangely well preserved while a handful of its fellows rot nearby. Intricate pictograms across its surface depict the recipe for a fierce tonic, brewed from ffyrnig root pickled in boar bile. The glyphs can be learned by those patient enough to study them — and careful enough not to get the recipe lethally wrong.