Interacting with computer generated humans in virtual reality is becoming more popular with the current increase in accessibility of virtual reality head mounted displays and applications. However, simulating accurate behavior in computer generated humans remains a challenge. In this study, we tested the effects of full body behavior (Body Movement and Head Movement) in terms of viewers perception (comfortability with and realism of the computer generated human) using an animated computer generated human in virtual reality. Our findings imply the significant influence of body animation (excluding head animation) on both comfortability and realism of the computer generated human. 37.5% of the participants did not notice the exclusion of the head animation; implying the importance of body animations over head animations. Using the results, we derive guidelines on computer generated human design and realization as well as their influence on the viewer’s perception. Finally, we discuss the constraints that should be taken into account when animating in virtual reality.