Digital pets such as the Tamagotchi or Creatures are harbingers of a new kind of interactive character. They are characters that must maintain the perception of sentience over extended periods of un-scripted interaction in dynamic and noisy environments. This perception of sentience is created by the character’s behavior over time (i.e. what it does and how it does it) as a coherent, character-specific, expression of its motivational and emotional state and reflecting its acquired “knowledge” of its environment. Ultimately this means we must understand how to build complete, if simple characters. In this talk I will present the approach the Synthetic Characters Group at the MIT Media Lab is taking to address this problem. Borrowing ideas from sources as wide ranging as animal behavior to classical animation, I will describe our approach to modeling drives, emotions, perception and behavior in an integrated architecture, as well as how we address the problem of expressive motor control. But I will also argue that the issues of camera control and interaction need to be more than an after-thought and I will present our approach to each of these problems. Finally, I will show videos of our SWAMPED! project, an interactive virtual cartoon world in which the participant uses a wireless, instrumented stuffed chicken to direct a semiautonomous animated chicken as it interacts with a fully autonomous animated raccoon in a manner reminiscent of a Warner Brothers cartoon. SWAMPED! was part of the Enhanced Realities venue of Siggraph ’98 and was used by over 400 participants.