From Kook Science
Yahoo (sometimes translated as Devil-Devil) is an appellation for a cryptid of the Western Australian outback, the name reportedly used by local Aboriginals to describe a "hideous monster, of an unearthly character and ape-like appearance," which was said to "resembl[e] a man, of nearly the same height, but more slender, with long white hair hanging down from the head over the features, so as almost entirely to conceal them; the arms [are] extraordinarily long, furnished at the extremities with great talons, and the feet turned backwards, so that, on flying from man, the imprint of the foot appears as if the being had travelled in the opposite direction."
- Capper, Henry, ed. (1842), "Superstitions of the Australian Aborigines: The Yahoo", The Australian and New Zealand Monthly Magazine (London: Smith, Elder and Co.) 1 (2): 92-96, http://www.nla.gov.au/ferguson/14605988/18420000/00010002/21-30.pdf
- Superstitions of the Australian Aborigines: The Yahoo, p. 92.