Baba Yaga: The First Setting in Rassiya (2005)

From the Publisher:

The world's most famous witch awaits you! Step inside the land of Rassiya,and experience the folklore of a cold, northern land where nothing is quite as it seems. Living dolls spin perplexing riddles. Foul spirits lurk in cold swamps. Talking wolves lure unwary travelers deep into forbidding forests. And there, at the heart of darkness, lives the black-toothed hag Baba Yaga and her chicken-legged hut.

Will she aid you in your journey, or devour your living soul?

This sourcebook contains: maps that cover the land of Rassiya; a detailed description of the town of Derevnya, giving adventurers a base of operations for exploring the land around them; never-before-seen monsters based on real Eastern European folklore; a brand-new playable PC race, the Lebedinoe; randomized charts for generating traps and magical items on the fly; and an in-depth look at Baba Yaga herself.