The sources describe the term kalku (Calcu) as a borrowing from the Puquina language and situate the concept within longer-range parallels between Mapuche and Central Andean cosmologies (the article links adoption of the term to historical contacts dating to the Tiwanaku period). Beyond the loanword note, the provided material frames kalku as a culturally recognized category of human practitioner rather than providing a specific mythic origin tale.
The provided sources do not give a physical description of individual kalku as human practitioners. What is documented is their affiliation with spirit-servants (for example, Anchimayen) and that the Chonchon is described as the magical manifestation of a more powerful kalku; sources do not state that all kalku have a visible or stereotyped human appearance.
Kalku work with wekufe ('spirits or wicked creatures') and with negative or 'black' magical forces. They command or employ harmful spirit-agents and other subordinate supernatural beings; named associates include the Anchimayen and the Chonchon (the latter described as the magical manifestation of a powerful kalku). The role may be inherited, or a machi may become a kalku by pursuing lucrative or transgressive practice and ignoring the admapu (the Mapuche rules).
Weaknesses
- otherNo specific vulnerabilities recorded in provided sources
Wards
- otherNo specific wards or protective rites against kalku are recorded in the provided sources; machi (benevolent ritual specialists) are indicated as the culturally authorized responders to malevolent forces

Wekufe
In Mapuche cosmology the wekufe (wekufü) is a class of harmful external force or spirit whose essential quality is to disturb or destroy the natural and social order. The term covers a range of beings and energies—from extracorporeal disruptive forces to material monstrous forms—and is tied to ritual order, sorcery (kalku), and healing practices (machi, machitún).

Anchimayen
Anchimayen is a small, childlike luminous creature in Mapuche mythology described as a servant or familiar kept by a kalku (Mapuche sorcerer). It is said to take the form of small children and to transform into flying fireballs that emit bright light; some sources also describe a later conception as a fuego fatuo (will-o'-the-wisp)-type being that can frighten travelers.

Chonchon
A Mapuche legendary being described as the detached, flying head of a sorcerer or person who has entered into sorcery. The chonchon is associated with kalku (evil sorcerers), nocturnal covens, and functions as an omen-bearing, predatory extension of illicit witchcraft in southern Chile and Argentina.
Community Record
- [1]Kalku — Wikipedia. Wikipedia, 'Kalku' article (accessed source material provided)wiki
- [2]Kalkun (Wikidata entry Q41988347). Wikidata entry noted in source list; does not contribute mythological detailswiki