To become an omnivore, even if your cell stage development chart makes you a carnivore or herbivore, do the following. Explore in cell stage until you find a cell with an omnivore mouth, which looks like a tube, and acquire it. Once you have it, evolve into creature stage normally, but do not delete the mouth. Shrink it and hide it behind another part. Then, even if the mouths you are allowed to select from are not omnivore mouths, you still have the omnivore mouth from the cell stage. This is useful in several ways. For example, if you are a carnivore all the way through cell stage but you want to make friends in creature stage you normally cannot. You have to eat at least some creatures to survive.