In Hesiod’s Works and Days, Pandora is the figure who opens the container. The poem describes her as the first woman, created by the gods and sent to Epimetheus after Prometheus’s theft of fire.
Hesiod does not give the later, elaborate scene of a single dramatic key turning in a small box. Instead, the account says that Pandora removes the lid of the great storage jar, releasing the evils that had been contained inside. The surviving text links the act directly to her curiosity or action, depending on how the passage is translated.
Epimetheus is important because he accepts Pandora despite Prometheus’s warning not to receive gifts from Zeus. That makes him part of the story’s chain of events, but he is not the person who opens the vessel. Prometheus, meanwhile, is connected with fire and divine punishment rather than the opening itself.
Later retellings often expand the episode, but Pandora remains the canonical opener in the ancient literary version most responsible for the modern expression.