Decades ago, witnesses reported a fearsome cryptid outside of the quiet River Kingdoms town of Shimmerford. Dubbed the Mosquito Witch, it was rarely seen since and quickly became a beloved local legend that the town celebrates and promotes to attract visitors. But when recent attacks began savaging livestock and townsfolk alike, many have started believing the Mosquito Witch was real all along. The PCs travel to Shimmerford to unravel the cryptid mystery, but might they just become the witch's next victim?