Per my Wikipedia research:
"The word mascot has been traced back to a dialectic use in Provence and Gascony, where it was used to describe anything which brought luck to a household. It is suggested that the word is derived from the French word masqu (meaning "masked" or "concealed").
The word was first popularized in 1880, when French composer Edmond Audran wrote a popular comic operetta titled La Mascotte. However, it had been in use in France long before this, as French slang among gamblers, derived from the Occitan word masco, meaning "witch" (perhaps from Portuguese mascotto, meaning "witchcraft"), and also mascoto, meaning "spell."
Audran's operetta was so popular that it was translated into English as The Mascot, introducing into the English language a word for any animal, person, or object that brings good luck. The word with this definition was then incorporated into many other languages, although often in the French form mascotte."
Also I found out there is a "Mascot Hall of Fame" which sounds awesome. There are only eight university mascots as members but unfortunately one is another Big 12 team.
http://en.wikipedia.org/wiki/Mascot_Hall_of_Fame