Chief Illiniwek was the university mascot, but they like to classify the Chief as a symbol. Chief Illiniwek was retired in 2007 amid concerns that the costumed performer was offensive to Native Americans. The Illinois marching band still plays the music the Chief used to perform to, and people wearing the costume have appeared in the stands during games while the music played. All that, of course, is unofficial.
"The school's decision led the NCAA to lift sanctions that had barred Illinois from hosting postseason sports since 2005. The NCAA had deemed Illiniwek -- portrayed since 1926 by students who cavorted at home football and basketball games in buckskin regalia -- an offensive use of American Indian imagery."
"Chief Illiniwek was the symbol of the University of Illinois at Urbana–Champaign (UIUC), associated with the University's intercollegiate athletic programs, from October 30, 1926 to February 21, 2007. Chief Illiniwek was portrayed by a student to represent the Illiniwek, the state's namesake, although the regalia worn was from the Sioux. The student portraying Chief Illiniwek performed during halftime of Illinois football and basketball games, as well as during women's volleyball matches.
For more than two decades, Chief Illiniwek had been the center of a controversy between fans and alumni who view "the Chief" as part of UIUC tradition; while Native American individuals and organizations, social scientists, and educators view such mascots as cultural appropriation of indigenous images and rituals, which perpetuate stereotypes about American Indian peoples. In 2005, Chief Illiniwek was one of 19 mascots cited as "hostile or abusive" by the NCAA in a policy that banned schools from full participation in postseason activities as long as they continued to use such mascots."
"The University of Illinois retired Chief Illiniwek in 2007, with his last official performance on February 21, 2007. However, the controversy has continued because UIUC has not selected a replacement, while an unofficial "Chief" continues to appear at games and other events. A non-binding resolution to make "Alma Otter" the official mascot was placed on the spring 2019 student election ballot, but failed to receive a majority, although some see the vote as a sign of progress. In 2020 the belted kingfisher received a majority of student votes as a possible new mascot. In September 2020 the University Senate overwhelmingly endorsed the kingfisher as the new mascot, voting 105 to 2 with 4 abstaining."