The image above portrays a Matuasto (upper left) and a regular lizard (bottom right), it was drawn at the basaltic plateau by Lake Buenos Aires in northwestern Santa Cruz province, Argentina.
The natives depicted their staple food (which they hunted on foot until the late 1600s, and then on horseback) such as guanaco (a South American camelid similar to llamas an vicuñas), and the South American rhea (an ostrich-like flightless bird). They also represented human steps and hand marks, and geometric shapes. But, why would they draw lizards? And not only one, but two varieties? What was so special about the Matuasto?
Midget monster, the Matuasto lizard
I had mentioned this lizard in a previous post (The Horse-Eating frog - Chile), but did not provide much information. Today we will go a bit deeper:
Matuastos (Diplolaemus darwinii) are found in Chile and Argentina, where it ranges from Patagonia in the south, through Cuyo (Mendoza, San Luis and San Juan provinces), Catamarca, Santiago del Estero and Tucumán provinces.
The word is of Quechua origin, a language not spoken in Patagonia but in Peru, Bolivia, and to a lesser extent, the norhtern reaches of Argentina. It was the language of the ancient Inca empire. Its meaning is "homeless" or "whose cave is not known". Which is quite reasonable, since lizards run around the ground, from here to there.
The interesting point is that it is widely feared. For instance, outside of Patagonia, in San Luis, it is regarded as poisonous and capable of giving a terrible bite; once it closes its jaws, it cannot be removed. It holds fast to its unfortunate prey.
Just for the record, it is NOT poisonous.
In San Juan and Mendoza (also outside of Patagonia) there is a myth about a woman Pericana who morphs into a giant matuasto and devours children.
The main features of this small "monster" is its short tail and stout body, a big squat head and very powerful jaws.
What is even more surprising is that such a small animal (it grows to about 5 to 9 cm long - 2 to 5.6 in.) can stir such great fears!
It was a widespread myth, and found in Patagonia, because, the creature was mentioned by British explorer George Musters who in 1870, after traveling from Punta Arenas to Carmen de Patagones with a band of Tehuelche, wrote:
Another animal supposed to be possessed of magical powers is a flat toad-like lizard, which is believed to lame horses by mysterious agency, and is killed whenever met with. 
The Tehuelche natives of eastern and southern Patagonia named it "k'amter", so this is what they must have told Musters that it was called.
Fernández,  records that the Mapuche natives took them for creatures possessed by "evil spirits" (snakes fell into the same category). The Mapuche word for it was "kirke", which simply meant: "lizard".
The Mapuche people at Neuquen province, describe it as a lizard with a stunted tail that is "aggressive and poisonous, that can jump, and once it has bitten it will not let go". 
The bringer of fire
The creature is also mentioned in a Tehuelche myth, as the one who invented the use of fire. The native group of Quilchamal, Tehuelche who speak Mapuche language (there was a process of Araucanization in northern Patagonia by which the Mapuche culture and language was adopted by the Tehuelche, even though they belonged to two distinct ethnic groups). This tribe lives in the province of Chubut, in Argentina.
One of the natives, Alberto Quilchamal recorded the legend, in which the Patagonian hare (mara) steals the flames from a matuasto (which Alberto calls kirke), he describes the lizard as "harmful and poisonous: 'they live from poison, the poison they have does not let them die'.", that is, they were immortal. Furthermore, to be able to kill them, they should be burnt (like European witches) or they will not die. 
The matuasto is therefore immortal, the inventor of fire, a poisonous, jumping strong jawed monster. Possessed by evil spirits and evil itself. The question is: Why? Why endow such a tiny lizard with such a repertoire of evil powers?
Perhaps not so tiny
I have seen the rock art at Cueva de las Manos (where I took the photograph shown in the horse-eating frogs post mentioned above), and these paintings were big. And by big I mean about 40 cm (3.3 ft long) and about the same width (look at the adult human hands stamped beside the images to get a sense of size). Those would be really big lizards. And also look at their clawed paws. Nasty indeed.
Could there have been some giant matuasto living in Patagonia in Paleo-Indian times?
For the time being I have not found any evidence or myths to support this notion, but who knows, maybe I will find something.
 Eduardo E. Berberián and María Ester Albeck, (2001), Historia argentina prehispánica. Ed. Brujas. vol. 1. pp. 856, Fig. 6, image 14. After Gradin (1993).
 Juan Wenceslao Gez and María Estela Gez de Gómez, (1939), Geografía de la provincia de San Luis. Ed. Peuser. vol. 2, pp. 96.
 Musters George Chaworth, (1969). At home with the Patagonians: a year's wanderings over untrodden ground from the Straits of Magellan to the Rio Negro. (1869).Greenwood Press, pp. 182.
 César A. Fernández, (1999). Cuentan los mapuches. Ed. Nuevo Siglo. pp. 14a
 Ana Fernandez Garay and Graciela Hernandez, (1999). Origen y uso del fuego
mito recogido entre los tehuelches araucanizados de la patagonia argentina, Amerindia, N°24, 1999.
 Marcos de Estrada, (1985), Leyendas y supersticiones sanjuaninas: contribución al estudio del folklore en la Provincia de San Juan. BPR , pp. 119.
 Gregorio Alvarez, (1981). El Tronco de Oro. Siringa Libros, pp. 295
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia2010 International Year of Biodiversity Copyright 2009-2010 by Austin Whittall ©