The shadow agent is a new type of intelligent virtual agent exploiting the metaphor of the shadow as a medium. The core of the shadow agent is a behavioral architecture inspired by the BDI (Belief, Desire and Intention) cognitive agent model. The shadow agent perceives the world through two video cameras and a microphone. Advanced computer graphics techniques are used to locate the user's feet and analyses his/her behavior. The shadow agent is embodied as an animated silhouette projected on the floor using the Everywhere Display system and is endowed with simple sonic behavior. While presented as an interactive installation, this model is thought to be a generic approach that can support many more applications, including: video games, museum guides and digital performance to name a few. Categories and Subject Descriptors I.2.11 [Artificial Intelligence]: Distributed Artificial Intelligence