How are the complex and varied body plans of animals generated during embryonic development? Coordinated cell shape changes and cell movements, which constitute morphogenesis, generate the structure of tissues and organs of all animals. Concomitant with morphogenesis, is the specification of the germ layers, leading to the assignment of cell fates. Together, morphogenesis and cell fate specification underlie the transformation of a simple cleavage stage embryo into a complex, well-patterned adult, and when they go wrong, profound patterning defects result. Remarkably, the astonishing diversity of animal forms arises from a limited set of cellular processes that are shared by animal species. Thus, by examining these processes in the experimentally tractable zebrafish embryo we can learn about fundamental cellular properties and mechanisms of morphogenesis and tissue patterning that are likely to be widely used throughout animal development.