This is the story of Sheshanga, the endless snake

Shesha appeared in his true form as the magnificent many-hooded snake and reared up his heads above Vasudeva, forming a protective umbrella over the child who was no other than Lord Krishna He was all-powerful, he was as old as the universe, he was the wise serpent-king. Sheshanaga, the endless snake, was a celestial being with the power of a deva. He carried the underworld on his many hoods and Lord Vishnu himself rested on his immense coils. Read about his multiple avatars and magical transformations