Poroniec

In Slavic tradition porońce are thought to come into existence following the death of a fetus (stillbirth) or from infants who died and whose remains were improperly buried. Folk accounts indicate that treatment of the remains affects outcome: a stillborn fetus buried under the house threshold was said not to become a poroniec but instead to become a kłobuk, a protective household spirit. Belief in porońce is therefore tied to customs and taboos surrounding pregnancy, childbirth, and burial.

Source accounts do not provide consistent physical descriptions. Modern summaries describe porońce as 'hostile and malicious' and 'extremely powerful,' but no detailed size, form, or visual traits are recorded in the cited material. Folkloric comparisons note similarity to other child‑derived revenants (e.g., the Scandinavian myling) which in other traditions are sometimes depicted as ghostly child figures.

Cited sources emphasize hostility and dangerous potency rather than specific magical feats. Porońce are portrayed as malicious toward people and 'extremely powerful' because they embody the potential of unrealized life. Belief in porońce influenced many taboos and preventative practices aimed at protecting pregnant women, infants, and households; specific combative or supernatural actions are not detailed in the provided sources.