Final answer:
Persephone was the one who returned to the underworld after eating pomegranate seeds.
Step-by-step explanation:
In Greek mythology, the answer to your question is Persephone. After being kidnapped by Hades and taken to the underworld, Persephone ate six pomegranate seeds which bound her to the underworld. As a result, she had to spend six months of every year in the underworld with Hades, and the other six months on earth with her mother Demeter.