A poor brahmin and his wife encountered a serpent in the woods. The serpent ate the brahmin!
The wife wept. "How will I live now?"
The serpent spat out a golden cup. "Beg alms with this. If anyone refuses, his head will explode."
"Then I beg you: return my husband, or your head will explode!"
The snake spit her husband out, and then turned into a gandharva, a heavenly being. "I was cursed to be a serpent until a woman outwitted me."
As the gandharva flew upwards, jewels rained down, so the brahmin and his wife were beggars no more.
Inspired by: The Ocean of Story by Somadeva, translated by C.H. Tawney: Volume 5.
Notes: This is Story 118. In the story, the snake is King of the Vidyadharas, but I just made him a gandharva. You can read more about vidyadharas and gandharvas at Wikipedia. The story starts with the brahmin and his brother; when the brother refuses to give him money, the brahmin is reduced to begging.