The paper presents a design and its implementation on a physically based animation of a lovely squirrel mascot playing Chinese Tai Chi. The work result was from a project aiming at an application of motion tracking technology to generate physically based animation for the Macao 2005 East Asian Games, in which the mascot called Pak Pak will play Tai Chi inside a virtually constructed Macao Sports Dome. This paper describes the modeling of the virtual character Pak Pak as well as some issues in applying the motion data captured to animate the character. Some solutions on modeling the complex part of squirrel shape and on the solution of fitness problem of human data applied to squirrel character are also proposed. We will go through both the ideas and technical detail on the solutions. A complete animation on the fly-over of the sports dome as well as the lovely Pak Pak playing Chinese Tai Chi will be presented along with the paper presentation.