The sign Scorpio used to be known under different names, the snake and the eagle. In the Christ zodiac where the 4 main apostels are the corners of the zodiac, John is represented as an eagle. (John is symbolically represented by an eagle, one of the creatures envisioned by Ezekiel (1:10) and in the Revelation to John (4:7))
Read more on Scorpio here:
http://www.gods-and-monsters.com/scorpio-mythology.html
