He was an anthropomorphic Cayenne pepper (a staple spice of the Acadiana region in which the school is located).
In recent years the university has had several mascots including live bulldogs (when the athletic teams were named the Bulldogs), Mr. Ragin' Cajun (animated), and the Fabulous Cajun Chicken (the most popular mascot in the history of the school).
Cayenne was introduced in 2000, and changes clothes depending on what sporting event he's at, e.g., he wears a Ragin' Cajun football uniform at the football games, and a Louisiana basketball jersey for the basketball games.
[1] In 2017, Louisiana Director of Athletics Bryan Maggard announced that a new mascot would be unveiled within two years.
For Halloween 2020, the Athletic site’s social media posted a picture of a graveyard with the words “Cayenne” and “The Fabulous Cajun Chicken” (the former Cajuns’ mascot) on two graves, suggesting that Cayenne’s mascot is “dead” and not making a return.