A bunch of animals are gatehred around this old animal. I think it's in a human-sized church, but I could be wrong. The old animal may or may not have a book, again I could be wrong. And old animal tells them this story about the last humans.
Apparently the vegetarians and the meat-eaters had some kind of war, and it wound up killing them all. All the soldiers wore these gas masks, and the battlefield was really hellish. Like, in retrospet, I'm amazed my dad let me see it(I was like six at the time). It ended with the two last soldiers fighting as they sink into quicksand, killing them both.
This has been bugging me for a while. Does anyone know where it's from?