Io

Io (Ancient Greek: Ιω) was a Naiad from Greek mythology. She was a daughter of Inachus and Melia. Io had an affair with Zeus and she bore him two children, Epaphus and Keroessa. She married Telegonus later in her life.

Mythology
Io was loved by the King of Olympus, Zeus, who was already married to the jealous Hera. When Zeus would meet with Io, he would draw the clouds to cover himself and his lover. However, Hera knew what he was doing so she interrupted them during their tryst. When Zeus discovered that Hera was coming to interrupt them, he transformed Io into a white cow so as to try and trick his wife. Hera was not fooled but pretended to not know what was going on and demanded the cow as a gift. Not wanting to arise her suspicions, he gave Hera the cow and she tied her up to a tree and sent Argus Panoptes to guard her.

In order to save Io, Zeus sent Hermes to slay Argus Panoptes and release Io. Hermes did so by telling Argus Panoptes a never-ending story that was immensely boring until he fell asleep. After falling asleep, Hermes touched each of Argus Panoptes' eyes and kept him in eternal slumber. He then released Io and she fled across Europe and Asia until he reached Egypt because Hera sent a gadfly to continuously sting her.

At one point during her travels, she met Prometheus who told her that she would be returned to her human form and became an ancestor of the world's greatest heroes. When she reached Egypt, she was restored to her original form by Zeus and gave birth to their children, Epaphus and Keroessa. Later in her life, she married Telegonus.