Weird but true, it's probably edited in Flash, and they're using rendered backgrounds with painted in effects to make it look animated.

Dragon Prince or whatever it's named is the biggest culprit, but you see it all the time. I had to explain it to my wife when she got weirded out by the cows in Mystery Incorporated.

This is all time savers from trying to have consistency frame by frame. What's really weird is that most of the AI animations look like that, even when they're not supposed to.