Elsa (Frozen) of the song "Let It Go", with critics frequently calling her a "powerhouse". Attempts were made as early as 1937 by Walt Disney to adapt Hans Christian Andersen's fairy tale, "The Snow Queen", into a film. The tale focuses on two children, one named Gerda, who served as the basis for Princess Anna, and the other named Kai, who is "cursed with negativity" after his heart is pierced with a shard of glass from an enchanted mirror and is later kidnapped by the Snow Queen. However, Disney struggled with creating a believable, multi-dimensional adaption of the fairy tale's title character,
Frozen (2013 film) characters include Kristoff's reindeer companion Sven, horses, and wolves. The grunts and snorts for Sven were all provided by Frank Welker who was not credited in the film. Walt Disney Productions first began exploring a possible live action/animation biography film of author and poet Hans Christian Andersen sometime in late 1937 before the December premiere of its film "Snow White and the Seven Dwarfs", the first feature-length hand-drawn animated film ever made. In March 1940, Walt Disney suggested a co-production to film producer Samuel Goldwyn, where Goldwyn's studio would shoot the live-action sequences of Andersen's life and Disney's studio would