Luigi Serafini And The Codex Seraphinianvs
Serafini is an Italian graphic designer and architect who created a legendary book in the 1970's. It is of a completely fictional world with illustrations depicting peculiar lifeforms and a varied selection of other details addressing this imaginary world. It is written in a non existant language. It goes so far as to depict a rosetta stone which merely translates the text into another non existant language. If you're interested in hunting down this mysterious book, it apparently fetches 200 - 250 dollars at various internet book stores. For additional information on the book and the artist, check the links below.
11 pages from the codex
Codex Seraphinianus, Hallucinatory Encyclopedia
Official website of Serafini with a few bizarre images and animation.