It's hilarious that somebody did a death metal cover of a song from a Disney film for little girls. I hadn't even heard of the song before, but I looked up the original version from the movie so I'd have something to compare the cover to.
I think this is the same recording that B posted, but the video is of the band performing the song not the film. It's even funnier this way, knowing the origins of the song and watching these grungy guys bang their heads to it:
I found an instrumental metal cover of it. This is the best version I've heard:
I found a My Little Pony cover too. Apparently everybody's getting in on it. My nephew who's in the Air Force is a Brony BTW: