A hypothetical (or actual) future world. There are no oceans, rivers, or lakes. There are no trees, bushes, grass, flowers, or vegetation of any kind. The planet's surface is flat and featureless; an endless plain of sun-baked rock.
The only inhabitants of Lizard World are the lizards: squat, lumbering beasts with large jaws and thick tails. They slowly make their way across the endless desert in a kind of Brownian motion, occasionally bumping into or walking over eachother. Every lizard is the same. Since there are no other species of fauna or flora, the lizards must eat eachother to survive. This continues, somehow, in perpetuity.