George Romero's original version of Day Of the Dead.
The version that we see on screen is very different and scaled way back compared the original script he wrote. If I remember correctly, he couldn't get the funding required to make it the way he originally intended unless he went with an R rating. He wanted to make it Unrated, so he accepted a smaller budget and made the movie as we know it.
Here is the original script:
http://www.imsdb.com/scripts/Day-of-the-Dead.htmlI read it many years ago. I need to reread it sometime.