A cyber-character is a kind of artificial life inhabiting a virtual world. To be a life form in the virtual world, cyber characters need sensors and control systems. The sensor system enables the cyber character to recognize not only the virtual world but also the real world in such a manner that it can respond to user's commands. The control system provides the cyber character with life-like behavior by generating goals and plans, selecting appropriate actions, and finally by animating the character. Users may feel the cyber character to be alive because of its close interaction and smart performance. In this paper, a cyber-character system designed to provide users with a realistic feeling of an artificial life is discussed.