First credited film appearance of Clint Eastwood (Jonesey).
In Back to the Future Part III (1990), this film, Ma and Pa Kettle at Waikiki (1953) and Abbott and Costello Meet the Mummy (1955) are playing at the Pohatchee Drive-In Theater in Hill Valley on November 16, 1955.
With Donald O'Connor's DUKW (duck) having stalled for want of gasoline, Francis comes along and asks him, "Wanna sell a duck?" This clever play on words was a reference to a catchphrase of the late comedian Joe Penner, "Wanna buy a duck?"
While speaking to Lieutenant Peter Stirling/boatswain's mate Slicker Donevan (Donald O'Connor), Francis turns his head for only a moment to a wall, at which point his voice echoes. It appears that as Chill Wills' dubbed in the mule's voice, a rather painstaking detail was considered.