If Illinois were to come up with something original, would it be Otters? What would work, a la Badgers/Wolverines, etc? The 3 big schools in Florida all make sense. Georgia has nothing original - the G from Green Bay and the bulldog from Yale. Spartans is a great one, Gophers makes sense, if not strikes fear, lol.
What would make sense for Illinois? I've never been to that part of the country.