Question

Who was both a woman and a man at different times?

Hermes
Tiresias
Charybdis
Tityus

Answer 1

Tiresias, he was born a man, but one of the things he was known for was being able to change from man to woman back to man in an endless cycle.

Answer 2

It's not in the answers but it should be Athena because in the Odyssey, she was a men(Mentor of Telemachus), and then she revealed her true form, becoming a woman again