Quetzalcoatl is the Aztec name of the feathered serpent god (also known as Kulkulkan -- but if I remember my education on this, Kulkulkan is actually the name used by the Toltecs believed to inhabit the city of Chichen Itza). This is the same serpent-god whose shadow decends the stairs on the great pyramid at Chichen Itza on the Yucatan peninsula in Mexico.
You've all seen this pyramid before... it's extremely famous.
Here's a link:
http://www.sacredsites.com/americas/mexico/chichen_itza.html
ANOTHER interesting side story. Montezuma believed that the Spanish conquistador Cortes, was actually the god Quetzalcoatl. Hopefully I remember this story...
Apparently there was a prophecy that Quetzalcoatl would return to the land on a "giant raft" from across the sea (which is how legend records he had left centuries earlier and had vowed to return). Cortes, it turns out, lands on the just the right day for the prophecy and Montezuma is a superstitious king. The impressiveness of the ships and the spanish armor convince the natives that this is indeed the God spoken of in the prophecy.
The story is pretty interesting because Montezuma does eventually doubt Cortes is Quetzalcoatl and rebels -- his men killing several of Cortes' soldiers. But just after this happens, disease breaks out (owing to the fact that the natives are now exposed to new germs for which they have no immunities) and many get sick and die. This, having never happened before, and occuring *just* after they doubt Cortes' diety and rebel, causes them to believe that they were wrong to doubt him -- that he really is Quetzalcoatl, and that he's now taking his revenge.