1948 Rudolph the Red-Nosed Reindeer Film by Animator Max Fleischer
In 1947, American animation pioneer Max Fleischer made a technicolor animated short based on the original 1939 book from Montgomery Ward, Rudolph the Red-Nosed Reindeer, and in 1948, the short was updated to include a new (but now very familiar) song by songwriter Johnny Marks.
via Brain Pickings