Mr. Magoo's Christmas Carol is considered the very first animated Christmas special, predating Rudolph, the Red-Nosed Reindeer by 2 full years. Some misguided historians mistakenly claim that Carol was an episode of the prime-time series, The Famous Adventures of Mr. Magoo, but that is factually incorrect. Given the format of the special, however, maybe those historians can amend their findings and consider that Carol would actually be a pilot for Famous Adventures, which also debuted in 1964, but lasted just one season, and all but marked the end of the trail for UPA, which also produced the Magoo theatrical shorts.
Here, now, is the opening sequence to Mr. Magoo's Christmas Carol, uploaded by christmasman2004 to YouTube:
Jim Backus (Gilligan's Island) is joined by Jack Cassidy (later of He & She), Morey Amsterdam (The Dick Van Dyke Show), and the seemingly omnipresent Paul Frees (Rocky & His Friends), among others. Carol also marks the rare occasion for another UPA character, Gerald McBoing-Boing, to actually talk (actress Joan Gardner provides Gerald's voice), as he plays Tiny Tim. It is a little odd to see Magoo managing to work despite his visual disorder, but it works. The only other musical adaptation of Charles Dickens' "A Christmas Carol", that I can think of right off the top, would be the 1970 feature film, "Scrooge", with Albert Finney. Noted Broadway tunesmiths Jule Styne & Bob Merrill, composed the music for the cartoon, which, appropriately, was set on a Broadway stage. Who knew Magoo knew anything about acting back then?