The Vetala, in Hindu mythology, is a vampiric spirit that inhabited corpses to cause mayhem in their village. The description given is that the vetala appears to be an anthropomorphic bat. Here, I made the Vetala look like a bat possessing a corpse. From there it will be able to manipulate the corpse as a puppet and even change its physical form at will, but overtime the cadaver will loose its original form and ability to shapeshift. Causing the body to mutate into a more bat-like creature and causing the spirit to seek a new host so it may not arouse suspicion.