Hinduism found energy and matter can be converted mutually . Initially universe was all in the form of energy except Lord Shiva and it was called Shakthi or Parvathi . Parvathi formed Lord Ganesha out of the condensed energy particles. read more
Actually there are several Puranic stories about Lord Ganesha and his elephant head. These stories are: 1. Once Parvati, just for fun, prepared an image of a child with an elephant's head, out of the unguents smeared over her body and threw it into the river Ganga. It came to life. read more