Abstract: A character modeling and animation system provides a simple, efficient and powerful user interface that allows the user to specify the complex forms of human beings by creating visual sequences of symbol boxes. Each symbol box encapsulates a set of modifications that is preferably applied to a generic musculo-skeleton system in order to achieve the desired human being. The musculo-skeleton is made of relational geometry representing internal human structures bones, muscles, fat. The system automatically generates natural looking 3D geometry by applying the contents of the symbol boxes to the musculo-skeleton. The same user interface is used to model and generate human hair and clothing. Different human beings can be produced by directly manipulating the boxes and their content. Natural form and motion is achieved by using the musculo-skeleton to drive the external skin envelope during animation. The resulting symbol sequences can be merged with other sequences to produce new human beings.