This book constitutes the first dictionary in the fields of East Slavic folklore studies and ethnolinguistics to catalog proper names appearing in Belarusian, Russian, and Ukrainian riddles. The material, collected and systematized by the author, significantly expands our understanding of the East Slavic worldview, as well as the typology of riddles and related genres. The first part of the book provides information on which proper names are employed to encode specific phenomena. The second part is devoted to instances where proper names are utilized for purposes other than encoding.