Trehuaco is a Mapuche word, which in their language (Mapudungun) means “water dog” (“trehua” = dog and “có” = water).
They are fierce, strong and big dog-like animals that live in lakes and rivers. Their dark fur is shiny and abundant and some believe that it was inspired by the Patagonian otter or huillin.
Folklorist Bertha Koessler-Ilg recounts a story about a “a strange dog” that some natives noticed:
swimming in the river […] that hunted fish and drove them to an opening in a rock that was placed above the river […] they had never seen a dog like that one […] it was a big ‘Trewa’”. When they tried to capture it and one Indian caught it by its foot, but the dog “bit him strongly and disappeared in the [deep] rapids
The unfortunate Indian later died from his wound.
It was also called a river dog (“Leufu Trehua”) and known as “Ngaqiñ” in the north and “Ponono” in the south of Chile. Chilean folklorist Guevara described it as a mythical creature that snarled and barked, making a noise that sounded like “hera-cac”; it lived in underground caves close to the water.
Its bizarre appearance was, according to the Mapuche, “perimontun”; against the laws of nature.
It was also seen in a lake by Yaldad, in the south of Chiloé Island, and described as a dark dog-like creature, with shiny hair and powerful muscles that came out of its aquatic domain to seduce and mate with the women who happened to come too close to the magic lake.
 Koessler-Ilg, B., (2000). Cuentan los Araucanos: Mitos, leyendas y tradiciones. B. Aires: Del Nuevo Extremo. pp. 116.
 Guevara, T., (1925). Op. Cit. Chap. I.
 Cárdenas, R., (1978). Apuntes para un diccionario de Chiloé. Ediciones Aumen. pp. 85.
 Source Internet. Author, unknown.
Copyright 2009 by Austin Whittall ©