Set your beasts free, and see if they come back.

Artist is James Belsar, I was looking for a strange animal, but you can pretend this is the eye of one.

New York Times, October 8, 2006
Electronic Arts’ forthcoming Spore game will allow you to “create an world that is entirely yours: the creatures, the vehicles, the cities, the planets,” says designer Will Wright.
Those layers map onto different spatial scales that you advance through as you play: cell, creature, tribe, city, civilization and space.
As you work your way through the Spore levels, your creatures are automatically sent back to the central Spore file servers, where they are then used to populate the worlds of other players.
When you land on a new planet in the game’s final stage, it may be teeming with multiple exotic species, all of whom have evolved separately on other computers around the world, guided by the tastes and imagination of complete strangers. But these creatures will, crucially, have lives of their own once they have found their ways onto your machine. They will not be controlled by other players as you interact with them on your screen.
Once they have migrated to your computer, they will act autonomously, based on the procedural animation and artificial-intelligence algorithms of the Spore software. By the same token, the creatures that you have lovingly brought to life will spread throughout the alternate universes of other Spore players, struggling for existence on their own, independent from your direct control.