From Wikipedia, the free encyclopedia. Chill Theodore Wills (July 18, 1902 – December 15, 1978) was an American film actor, and a singer in the Avalon Boys Quartet. He was a performer from early childhood, forming and leading the Avalon Boys singing group in the 1930s. After appearing in a few westerns he disbanded the group in 1938, and struck out on a solo acting career. One of his more memorable roles was that of the distinctive voice of Francis the Mule in a series of popular films. Wills...