Biami is one of the most important male Spirit Ancestors in south-eastern Australia. He was given his spirit form by the Rainbow Serpent during the Dreamtime and is incorporated into male initiation ceremonies. Even though Biami initially roamed the earth and guarded the tribespeople, he is now considered to be a Sky God and watches over the earth from his home in the sky. In this myth about Biami and Mirrabooka, the origin of the Southern Cross constellation is described.
Biami the good spirit was kept very busy, guarding the tribes as they roamed throughout the earth, and he was very much troubled for them. He found that he could not watch over all of them at once; he knew he must have help to keep them from harm. Among the tribes there was a man called Mirrabooka, who was much loved for his wisdom, and the way in which he looked after the welfare of this people. Biami was well pleased with Mirrabooka, and when he grew old, promised him eternal life. Biami gave Mirrabooka lights for his hands and feet and stretched him across the sky, so that he could watch forever over the tribes he loved. And the tribes could look up to him from the earth and see the stars which were Mirrabooka’s eyes gazing down on them.
There are considerations that the Christian attainment of eternal life through crucifixion also has basis in Southern Cross cosmolgy, as well as other such mystery symbols such as the Egyptian Ankh, but there are no direct confirmations of such.