This is the "Ghost Army" sequence from The Return of the King.
I watched it as a refresher while preparing the following decode.
I didn't intend to post it, but then I realized that it parallels the Betty Boop video.
There the guards Bimbo and Koko turned from the service of evil to do good.
But here the murderers and traitors (living a half-life) are given a chance at redemption.
They take it.
Or you could take the ghosts as resembling an army of frogs.