Based on the idea that animation art materializes the world of animism, which is the epistemological approach of identifying the presence of spirits and the action of life within all things, it is essential to comprehend how the body, as a place where life manifests itself so that the ‘plausible impossible' imagery of life continues, follows its own physics in animation, which has been refined through animation history. This paper tries to explain how the animated body is first formed, and then acts out, by analyzing the specific example of ani-body of Mickey Mouse in Steamboat Willie (1928) by Disney.