This appears on various folklore and cryptozoology sites as an illustration of a bunyip. None I can find credit an artist or source. It has a 19th century look to it, but that’s just speculation.
If you know who the artist is or where to find a higher quality copy of this image, please reblog with info.
i have no idea if you’re still looking for the artist or the source, but two sites say this is a piece by an ainslie roberts! this is his wikipedia, and site. he has lots of interesting works, and this piece was in a book called Bunyips: Australia’s folklore of fear. i don’t know much else but if you want i found a cute site about bunyips too.
After months without answers, two bloggers recognized the art on the same day. Dotesmite identified this as one of the interior illustrations in The Dawn of Time, a book of indigenous Australian myths by Charles P. Mountsford first published in 1969.