The purpose of this experimental study was to test the role of image and animation on: a) learners' perceptions of pedagogical agent persona characteristics (i.e., extent to which agent was person-like, engaging, credible, and instructor-like); b) agent value; and c) performance. The primary analysis consisted of two contrast comparisons: 1) comparing the presence/absence of agent image; and 2) comparing static versus animated agent images. In the study, 75 preservice teachers developed an instructional plan for a case study involving designing economics instruction for the concepts of supply and demand within the MIMIC (Multiple Intelligent Mentors Instructing Collaboratively) agent-based environment. Overall, animation was found to be beneficial for all four persona characteristics, but not always as the single best implementation. For the agent to be perceived as instructor-like, a strong positive effect was found for the presence of agent animation. Agent credibility was facilitated by either a static or animated image, with the presence of an image being critical. Perceptions of the agent as engaging and person-like were also improved by animation, although person-like was not affected by presence/absence of image. Results are discussed in terms of implementing anthropomorphic pedagogical agents to support computer-based instruction. (Contains 4 tables and 2 figures.)