from what i can remember - i watched it around 1994 so it could be made any time before that. it was a cartoon, either a tape with mini movies or one big movie i can't quite remember but it was scary. there was a scene where a man (think horse and carriage era) and a horse drawn carriage pulls up with black stallions. inside is a skeleton with a robe on. i know this is pretty vague but anything will help thanks! Oh and it is NOT the black cauldron

That sounds pretty radical. Once you figure out what it is, let me know too.
(P.S. Skeletons are awesome)