Metis

Metis was an Oceanid, and daughter of Oceanus and Tethys. She was also the first wife of Zeus. Metis was the goddess of wisdom and deep thought. Metis was also responsible for giving Zeus the potion that caused his father to expel Zeus' siblings. As had been prophesied for his father and grandfather, it was said that Metis would birth Zeus a son 'more powerful than Zeus himself' who would overthrow him. In order to prevent this from happening, Zeus turned Metis into a fly and swallowed her. Metis, however, had already conceived a child. Athena leaped from Zeus's head fully grown, armed, and armoured.