In immersive virtual reality simulations in which users are immersed into full body humanoids, it is typically the case that the humanoid size and proportions have to match those of the immersed user for the immersion to be realistic. However, a key aim of these simulations may be to study how users of different body sizes and proportions interact with the environment. We have developed a real time motion retargeting method by which users can be immersed into different humanoids and other kinematically similar avatars, and still experience a realistic feeling of immersion. A set of experiments aimed at studying the realism of the immersion indicate that users indeed experience a realistic sense of immersion into different humanoids.