Dark Oak

From the publisher's website:

A Pathfinder Roleplaying Game compatible GM’S RESOURCE adventure for 5th-level PCs by Creighton Broadhurst and Steve Hood

Beneath the fetid roots of a noisome swamp linger the pathetic remnants of a once proud and noble tribe. Laid low by a powerful narcotic administered by their ambitious (but wildly paranoid) mistress, the lizardfolk of the Dark Oak are but a shadow of their former greatness. Now below the slumbering body of a diseased treant she plots to bring bloody slaughter to the folk of the nearby villages before her followers forget their proud heritage and sink into a lethargy from which there is no escape.