What editor? (Spore)

In the game at the beginning, click on the EDITORS and create creatures adding them to sporepedia. For what? As they then add on the planets to meet up to make friends with them or kill them.
And why if I choose to create a being for the stage creature, the designer only legs and a set of cells, because the creature stage ect doesn't work, why would I create a creature with eletrosul which will only take up space and don't perform their functions ???