There are millions of species of animals on the planet. Many of them can seem like aliens to us because they are so different. All animals need to fulfil the same tasks as we do and there are fascinating ways to do so. Building an animal that is composed of many cells — the units of life — is not an easy task. Each animal is build from a single cell at its beginning and all other cells descent from this and form all the important tissues and organs. Cells need to be positioned at the right place, where they are instructed to specialize for fulfilling special tasks. These processes are fascinating and recent research has given deep insights into how animals are made. This process of making an animal from egg and sperm seem to repeat a process of how animals arose on planet earth during evolution. How did multicellular animals emerge from microbe sized single celled organisms? What are the major inventions that led to the arousal of large animals such as bumblebees and fish? Where lies the origin of the brain, the gut and other organs?