The Oceanid Metis, Titan goddess of good counsel, advice, planning, cunning, craftiness and wisdom, became pregnant by Zeus, who then, fearful of a prophecy about a son she might produce, swallowed her and the unborn. In this way, Zeus became pregnant with the future goddess Athena.
When it was time for her delivery, she started pounding, from the inside, on Zeus’ head. Either his (step-)son, the smithy god Hephaestus or Prometheus (either of whom would have jumped at the opportunity to inflict pain on the king) struck open Zeus’ head with an axe to release the goddess. The goddess emerged fully armed.
The term Parthenogenesis comes from two Greek words, one for virgin (parthenos), a title given Athena (Athena Parthenos), and the other, a familiar word for creation (genesis).