In this paper, we describe a system that can build 3D animal models and synthesize animations in 3D virtual environments. The model is constructed by 2D images captured by specific views. The animation is synthesised by using physical motion models of the animal and tracking data from image sequences. Finally, the user selects some points of the 3D world and a smooth and safe motion path, which passes by these points, is created. The main assumption of the 3D modelling is that the animal could be divided into parts whose normal sections are ellipses. Joints and angles between skeleton points are used in order to decrease models complexity. Using the above methodology, a snake, a lizard and a goat are reconstructed.