In mythology, the character who is known for transforming into a widow following her husband's death is Inanna from Sumerian myth. After descending into the Underworld, Inanna loses her partner, Dumuzi, due to his inability to mourn her adequately. This transformation symbolizes the deep connection between love and loss, as well as the cyclical nature of life and death. Inanna's journey explores themes of grief, rebirth, and the consequences of one's actions, reflecting the complexities of human emotions and relationships in mythological narratives.