Mickey Rooney was originally considered for a United Artists Francis feature film[3] before Universal-International acquired the rights.
The book and film series focused on the exploits of Francis, an experienced Army mule, and Peter Stirling (played by Donald O'Connor), the young soldier whom he befriends.
With a plot device like the later series Mister Ed, Francis would usually talk only to Peter, thus causing problems for his nominal "master."
As the titles indicated, each film had a different setting or gimmick, exposing the world-wise mule and the naive GI to race track excitement, the world of journalism, and many branches of the military, from West Point to the WACs to the Navy.
Stirling, with the sage but sardonic advice of Francis (gleaned from overhearing generals plan strategy or from discussions with other equines), would triumph over his own incompetence.
[6] The distinctive voice of Francis was provided by veteran character actor Chill Wills, who lent his deep, rough vocal texture and Western twang to the cynical and sardonic mule.
As was customary at the time, Wills never received billing for his vocal work, though he was featured prominently on-screen as blustery General Ben Kaye in the fifth film, Francis Joins the WACS.
To create the impression that the mule was actually talking, Hilton used a thread fed into the animal's mouth which would cause Molly to try to remove it by moving her lips, the same technique used for Mister Ed.
David Stern and Frank Thomas scripted a 1952–53 syndicated comic strip, Francis, the Famous Talking Mule, illustrated by Cliff Rogerson, who also drew the gag panel, Tee Vee Laffs (1957–85).
Seventeen issues of Francis the Famous Talking Mule were published as part of Dell's Four Color Comics series from 1951 to 1960, illustrated, alternately, by David Gantz and Don Gunn.