Lake Paimun is actually the northern arm of Lake Huechulafquen (which is the abode of the Huechulito lake creature), it is also close Aucapan (which is haunted by another monster).
With a surface area of 29.2 km2 (11.3 sq. mi.) it has a roughly semi-circular shape; it is 14 km (8.7 mi.) long and not more than 2 km (1.2 mi.) wide. A calm, deep lake, with a spectacular view of Lanín volcano.
Its name, in Mapuche language means "lacking love". It derives from the words Pay, the familiar and tender word that children use to name their mothers or older women that should be respected or loved; and the word mun, which means to need, to deserve. Hence, Paimun = orphan, who needs a mother, lacking love.
A rather strange name for a lake!
Paimun (39°43'S, 71°35'W) joins Lake Huechulafquen at the Angostura Pichi Cuyín (Small Apple Narrows), which is partly filled in by landslides along the valley of the Rucu Leufu River, which is fed by the glaciers on the Lanín Volcano (3.776 m - 12,380 ft.). These landslides must have provoked tsunamis in the lakes and severe flooding.
Trelque the "Cuero" of Lake Paimun.
According to local folklorist, Gregorio Alvarez, this tiny lake is said to be the home of a "lake genie" or Trelque. This creature lived in the deep waters of Paimun and stalked the women who came close to its shores.
Trelque is the Mapuche word for "hide" (in Spanish = Cuero); and I have written about the cuero in previous posts. However, it seems to me that this particular Trelque is not the usual kind of cuero.
The local myth, as told by Alvarez, is the following:
One day, while a young girl named Huala, was filling her flask by the lake, "a claw suddenly emerged from the shore and grabbed her firmly, dragging her to the deepest part of a pool [...] Huala, like so many others, had been submerged by the so called "cuero".
Huala was taken by Trelque to a cave in the deepest part of a sheer cliff, and there she saw the decapitated remains of other victims of this monster.
The story then goes on to tell that Trelque morphed into a handsome man and told Huala that he was in love with her, and that he would not kill her. As she wanted to go back to her home, he used his magic powers to keep her close but happy: he turned her into an aquatic bird, the Huala.
It is interesting to note that the Trelque creature, unlike the regular variety of Cuero, lived in a cave and out of the water, indicating an amphibious being. This is not a stingray, it is another kind of monster.
 Mancino, C., (2007). Thesis. Online
 Alvarez, G. (1969). Donde estuvo el Paraiso. Ed. Pehuén. pp. 167-169.
 Augusta, F., (1916). Diccionario Araucano - Español y Español - Araucano. Santiago. Impr. Universitaria. pp. 94.
 San Martín, F., (1919). Neuquén. Impr. Rodríguez Giles.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia2010 International Year of Biodiversity Copyright 2009-2010 by Austin Whittall ©