System and methods for defining and applying animations to virtual characters with interchangeable body parts that may be combined to form composite virtual characters are disclosed. According to aspects of the invention, a software program running on a gaming platform comprises a plurality of virtual characters, each comprising a plurality of interchangeable body parts. An animation clip may be defined for an interchangeable body part of a first virtual character. The animation clip may be defined for the first virtual character's interchangeable body party using a virtual skeleton that has the bones of the interchangeable body part and the bones of one or more generic body parts. The defined animation clip may control one or more of the bones of the interchangeable body part and one or more of the bones of the one or more generic body parts.