Last night I was telling Juliet about the stories of Vikram & Vaital that I grew up reading and watching on TV as a kid in India. Feeling that I didn't give her a good enough summary of the collection, I decided to look online and found something I didn't expect.
This is the part I knew: According to the stories, King Vikram promised a sorcerer that he would capture a vampire spirit, Vaital, who hangs from a tree in a desolate forest. Each time Vikram tries to capture the spirit, it tells a story that ends with a riddle. If the king knows the answer, he must answer and if he answers it correctly, the spirit would escape and return to his tree. If Vikram cannot answer the question correctly, the spirit consents to remain in captivity. King Vikram guessed the answer 24 times and the spirit flew away each time.
This is the part I learned today: On the twenty-fifth attempt, the spirit tells the story of a father and a son in the after-math of a devastating war. They find the queen and the princess alive in the chaos, and decide to take them home. In due time, the son marries the queen and the father marries the princess. Eventually, the son and the queen have a son, and the father and the princess have a daughter. The spirit asks what the relation between the two newborn children is. The question stumps Vikram. Satisfied, the spirit allows himself to be taken to the sorcerer.
In summary, the "I am my own grandpa" story is over a thousand years old and has roots in ancient Indian tales. And the Ray Stevens song based on the story is hilarious.