Without further ado, here are some animated GIFs that the game AUTOMATICALLY made (I didn't even know they existed until I was looking around my spore directory). These animations show some of the creation process that went into the different stages of my creature.
First, here's me, creating a Sandworm from scratch:

And here is the creation of my space ship, the Arturan Mega-Platypus, from scratch:

And now, a selection of important evolutions of my creature (there were more, this is just a small selection):



Here you can see how radically my creature changes through its evolution. You can watch as I add legs to my small creature. After that you can see me add arms. Then I add another set of arms, which eventually turns into a set of weapons. The mouth and overall bodily structure also changes quite a bit. I made most of those changes in order to give my creature better stats and help it survive better. When something didn't work right, I removed it. When something worked well, I did more of it. The player of the game is playing the role of Natural Selection. It's awesome and educational!
Also, I want to mention that there are some people who actually think Spore is "evil" because it "promotes evolution." I have one response. Spore "promotes evolution" the same way Super Mario "promotes gravity." Thank you, that is all.