Frosty the Snowman is an animated Christmas special that first aired on CBS on December 7, 1969. This special, written by Romeo Muller and produced and directed by Arthur Rankin and Jules Bass, is based on the holiday song of the same name, originally written by Jack Rollins and Steve Nelson and first performed by Gene Autry in the 1940s. The special involves a discarded silk top hat becoming the focus of a struggle between a washed-up stage magician named Professor Hinkle, and a group of schoolchildren after it magically brings a snowman to life. Realizing that newly-living Frosty will melt in spring unless he takes refuge in a colder climate, Frosty and a young girl named Karen, who he befriends stow away on a freight train headed for the north pole. Little do they know that the magician is following them, and he wants his hat back.
June Foray originally recorded the part of Karen, but was replaced by an unknown actress, a year after Frosty first aired; Foray recalled her experiences in the book The Enchanted World of Rankin/Bass: "I was called in to voice the little girl Karen. I was disappointed to learn later that my work for the Karen character was replaced by another actress. To this day I am unsure of the reason, but I still enjoy the special." Foray's voice can be heard on the Rhino Records soundtrack.
The original airing of the special with Karen's original voice is currently impossible to find on the internet. The album of the special's 1969 audio also contains additional instrumental music during the train scene.