Crowd Simulation and Visualization are an important aspect of many applications such as Movies, Games and Virtual Reality simulations. The advantage with crowd rendering in movies is that the entire rendering process can be done off-line. And hence computational power is not much of an overhead. However, applications like Games and Virtual Reality Simulations demand real-time interactivity. The sheer processing power demanded by real time interactivity has, thus far, limited crowd simulations to specialized equipment. In this thesis we try to address the issue of rendering and visualizing a large crowd of animated figures at interactive rates. Recent trends in hardware capabilities and the availability of cheap, commodity graphics cards capable of general purpose computations have achieved immense computational speed up and have paved the way for this solution. We propose a Graphics Processing Unit(GPU) based implementation for animating virtual characters. However, simulation of a large number of human like characters is further complicated by the fact that it needs to be visually convincing to the user. We suggest a motion graph based animation-splicing approach to achieving this sense of realism.