Below I copy the text written by an Englishman, Samuel Hull Wilcocke (ca. 1766 - 1833), who quotes unknown sources in his book about Buenos Aires (very likely he embellished the description given by father Faulkner) and descripes the Yaguaru.
Nevertheless, the donkey sized wolf headed animal, with talons, tusks and shaggy hair is quite odd, and gives us another depiction of this creature:
Yaguaru an Indian name signifying water tiger is the appellation given to a kind of amphibious animal inhabiting the river Parana which is very seldom seen and of which no accurate description has been given It is vaguely described as being of the size of an ass with a head like a wolf and stiff erect ears sharp talons and strong tusks thick and short legs long shaggy hair and a long tapering tail
The book's text is:
The above text is from: Samuel Hull Wilcocke, (1807). History of the viceroyalty of Buenos Ayres London. pp. 466.
The upright (Stiff erect) ears are quite different from those of other Patagonian animals said to be a "Water Tiger", such as the "tiny eared" Iemisch.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia2011 International Year of Forests Copyright 2009-2011 by Austin Whittall ©