Cáo (Hồ ly tinh)

No origin story for the Vietnamese fox spirit (cáo / hồ ly tinh) is present in the supplied sources. The materials provided include a Wikipedia article on the historical figure Cao Cao, a Wikidata entry noting Cao as a Chinese family name (曹), and several archived web pages unrelated to folklore; none of these supply mythological origins, creation narratives, or traditional genealogies for a Vietnamese fox spirit.

The supplied documentation does not contain any description of appearance for a Vietnamese cáo / hồ ly tinh. No physical characteristics, shapeshifting details, or iconographic traditions are present in the provided sources.

There is no information in the provided sources about abilities, powers, or typical behaviors of a Vietnamese fox spirit. The dataset supplied does not attest to any supernatural capacities or interactions with humans for such an entity.