You can download the blend file from google drive here:
Basically the scene wont render correctly. The tree leaves, torches and wheat crops in the scene should have their transparency working (i made a copy of the main material, then set it to Texture > Alpha Influence = 1 and set z-transparency on the object which in all other occasions has made the transparent bits go transparent, but this time it just isnt working for no reason.
Also, I added a creeper into the scene who should creep in and emit smoke from frame 100 to 125. While the creeper does this correctly, the smoke renders incorrectly, with parts of the background scene visible through the smoke. Why?
Additionaly, the creeper WAS visible, but now i decided to animate it, it appears to have gone completely invisible. Again, why?