In the game I am working on you will have entire ecosystems. Gone are the days of random spawners. With SpatialOS you will have real lifecycles. For example, mutant dogs will eat mutant flies which in turn allows them to poo. Mutant flies will lay eggs in the poo, hatching more mutual flies! The cycle of life will go on. Of course, players can mess with the cycle but there will be safeguards in place. But... genocide is possible!
In this shot you can see two mutant dogs chasing after a giant fly for a snack!