In the movie Santa Claus Is Comin' to Town, S.D. Kluger serves as the narrator and guide, answering questions from children about the origins of Santa Claus. He tells the story of how a baby named Kris is found by the toymaker elves and raised by them in the North Pole. As Kris grows up, he becomes determined to bring joy to children and decides to deliver toys to the children of Sombertown, despite the town's mayor, a strict and mean-spirited man named Burgermeister Meisterburger, forbidding it.
To avoid detection, Kris dons a red suit and white beard and travels by night, leaving presents for the children of Sombertown. However, the mayor eventually catches wind of Kris's activities and orders his arrest. Kris, now known as Santa Claus, narrowly escapes and seeks refuge in the mountains, where he encounters the reclusive and fearsome Winter Warlock. Through a series of kind and selfless acts, Santa Claus manages to melt the Warlock's heart and gain his assistance in delivering toys.
Despite the mayor's attempts to stop Santa Claus, he becomes beloved by the children of Sombertown, who call him the "jolly old elf" and eagerly await his visits each year. The movie ends with S.D. Kluger reminding children that Santa Claus is a symbol of love and generosity, and that by being kind to others, they can embody the spirit of Christmas all year round.