The giant tortoise in Hindu mythology that supported the world is named Kurma. He is the second avatar of the god Vishnu and plays a crucial role during the churning of the ocean (Samudra Manthan). In this myth, Kurma took the form of a tortoise to support Mount Mandara, which was used as a churning rod to extract valuable treasures and the nectar of immortality from the cosmic ocean. His steady support ensured the success of this divine endeavor, emphasizing the themes of stability and balance in the universe.