It was named after the curupira, a legendary Amazonian man-beast-like entity. This particular tepui stands 3,435 ft above sea level, and is situated on the Venezuelan-Brazilian border.
The curupira, as depicted in the painting 'O Curupira' by Manoel Santago, 1926 (public domain)
Conan Doyle had learnt about Kurupira from the famous, subsequently-lost explorer Lt-Col. Percy H. Fawcett. He had lately led an expedition to a much more famous tepui in the same region, Mount Roraima.
There are more than 100 tepuis in South America, and at 9,220 ft above sea level Mount Roraima is the highest (and also the largest) in the Pakaraima chain on the borders of Brazil, Venezuela, and Guyana.
My copy of Jaroslav Mareš's cryptozoological encyclopaedia Svět Tajemných Zvířat ('The World of Mysterious Animals') (© Jaroslav Mareš/Littera Bohemica)
The Waiká likened its body colouration to theirs too (i.e. green or golden-brown with darker markings), but its mouth is not as wide as that of these famously wide-mouthed frogs, and its skin is covered with hard, non-overlapping, tubercular scales. Above all, they affirmed that there is never any hope of escape if pursued by a stoa.
Artistic rendition of the possible appearance in life of the stoa, alongside a human for scale purposes (© Connor Lachmanec)
Restoration of the possible appearance in life of Carnotaurus (© Lida Xing and Yi Liu/Wikipedia CC BY 2.5 licence)
The still-classic (if scientifically-superseded) restoration of sauropods by Charles Knight, 1897 (public domain)