Where Disney stole his stuff

I saw a documentary on TV years ago that talked about European influences on Walt Disney's animation. To make a long story short, he stole everything. These ghostly riders are from Murnau's 1926 masterpiece, Faust. Compare and contrast to Night on Bald Mountain from Fantasia: except that these guys are a lot scarier. How did they do this, I wonder? Special effects were all manual then, but surprisingly creepy. Those horses, Jesus! (It took me years and years to track this clip down. I still can't find the documentary anywhere. I think it was originally in French.)