Upyr

Sources characterize the upyr as a folkloric revenant category rather than a single fixed origin narrative. Scholarly and popular etymological commentary links the lexical and conceptual forms to a Slavic–Turkic contact zone (with forms like 'онпыр' attested in Old Slavic/Turkic contexts) and suggests the belief spread across the Eurasian steppes through movements such as Kipchak–Cuman migrations. Traditional accounts and summaries tie becoming an upyr to problematic deaths in community terms (for example deaths involving lack of baptism or other unredeemed circumstances are discussed in later summaries), but the supplied corpus does not contain a single canonical cosmological origin myth.

Direct folkloric descriptions in the supplied material are limited. Nineteenth‑century tale-collections (for example Afanasyev's collected tale titled variously 'The Fiend / The Vampire / The Corpse Eater') present the upyr in corpse‑related narrative contexts and as a corpse‑eating figure. Later popular and secondary sources project common vampire imagery onto the upyr, but the excerpts provided contain no single stable physical canon for the entity.

Across the cited material the upyr is described as a harmful revenant that preys upon the living. Modern summaries and folklorist overviews call it a prototype of the vampire associated with blood-taking and with causing infant mortality, plagues, and crop failure in community accounts. A related Slavic subtype (wurdulac/vurdalak) is specifically reported in some sources as a vampire that attacks and consumes loved ones and converts family members; this motif appears in comparative discussions of Slavic vampire lore. The provided corpus links upyr activity to household affliction and broader misfortunes but does not supply exhaustive trait lists.