Jimmy Durante's final film (not counting documentaries and one short film appearance).
Voice actress June Foray was cast for both Karen and the Teacher and had recorded vocals for both characters. However, only her recordings for the Teacher made it into the final special as another actress was called in to replace Foray's Karen, for reasons that even Foray herself to this day does not know. No changes were made to the credits, so the actual voice actress we hear as Karen remains unknown and uncredited. Foray's Karen can be heard on the Rhino Records soundtrack.