"Sibi" from the Mahabharata
The legendary storyteller Vyasa Dvaipayana may be as mythical as the stories he tells. But in any case, the story goes that he created the Mahabharata, but needed a writer to record it. So he summoned the elephant-headed god Ganesha. He was displeased at being removed from his dinner. But Vyasa compliments him, and the flattered potbellied god agrees to do so. He comments on the story before it has even really begun, and Vyasa calls him obese and tells the story...