David Prebenna's Danse Macabre (Animation for PBS, 1985)

The YouTuber who posted this gave this introduction:

"This originally aired on PBS in the 1980s featuring a poorly made up vampire host to introduce and discuss.
It was also shown to me when I was in elementary school. One of the best short length Halloween animations ever created. Terrific illustrations.

About the song: Danse macabre, by French composer Camille Saint-Saëns, was an art song for voice and piano (first performed in 1872) with a French text by the poet Henri Cazalis which is based in an old French superstition. Two years later, the composer expanded and reworked the piece into a tone poem for orchestra, replacing the vocal line with a solo violin. The rest, they say, is history."