Animated characters are expected to fulfill a variety of social roles across different domains. To be successful and effective, these characters must display a wide range of personalities. Designers and animators create characters with appropriate personalities by using their intuition and artistic expertise. Our goal is to provide evidence-based principles for creating social characters. In this article, we describe the results of two experiments that show how exaggerated and damped facial motion magnitude influence impressions of cartoon and more realistic animated characters. In our first experiment, participants watched animated characters that varied in rendering style and facial motion magnitude. The participants then rated the different animated characters on extroversion, warmth, and competence, which are social traits that are relevant for characters used in entertainment, therapy, and education. We found that facial motion magnitude affected these social traits in cartoon and realistic characters differently. Facial motion magnitude affected ratings of cartoon characters’ extroversion and competence more than their warmth. In contrast, facial motion magnitude affected ratings of realistic characters’ extroversion but not their competence nor warmth. We ran a second experiment to extend the results of the first. In the second experiment, we added emotional valence as a variable. We also asked participants to rate the characters on more specific aspects of warmth, such as respectfulness, calmness, and attentiveness. Although the characters’ emotional valence did not affect ratings, we found that facial motion magnitude influenced ratings of the characters’ respectfulness and calmness but not attentiveness. These findings provide a basis for how animators can fine-tune facial motion to control perceptions of animated characters’ personalities.