We (the regiment I'm a member of in the Sealed Knot) sing a version of it with a lot more words than that, but to a similar tune.
THE WORM SONG
If you ever see a hearse go by, Remember the day that you must die
Oh, oh, oh, oh, where will you be in a hundred years from now?
They wrap you up in a clean white shirt, Then they cover you up with dirt
Oh, oh, oh, oh, where will you be in a hundred years from now?
You been in the ground for less than a week And then your coffin begins to leak
Oh, oh, oh, oh, where will you be in a hundred years from now?
The worms crawl in and the worms crawl out, They crawl in thin and they crawl out stout
Oh, oh, oh, oh, where will you be in a hundred years from now?
There’s one little worm that’s not so shy Crawls in through your ear and out through your eye
Oh, oh, oh, oh, where will you be in a hundred years from now?
Your eyes fall in and your teeth out, Your brains come dribbling down your snout
Oh, oh, oh, oh, where will you be in a hundred years from now?
And it’s oh, oh, oh, oh, where will you be in a hundred years from now?
DEAD!