Some are vital for survival, like spines and electric tails, and some just look cute.
At this point, you jump into one of the game's much-lauded Creators, in which you can add new body parts to your cell. You spear other lifeforms, eat their carcasses to earn DNA points, then mate with another bacteria and produce offspring.
You'll spend the first half-hour of your Spore experience in the 'Cell stage,' swimming around in the aforementioned prehistoric bisque.