The Great White Turtle (大白龜) is a giant turtle based in Heaven Reaching River (通天河). He was forced out of his underwater residence by the King of Spiritual Touch. Sun Wukong brings Guanyin to subdue and take away the demon. He feels so grateful to the protagonists for helping him take back his home that he ferries them across the 800 li river on his back. Before moving on, Tang Sanzang promises to help the turtle ask the Buddha when he will be able to transform into a human. However, Tang Sanzang forgets his promise when he arrives at his destination, Vulture Peak, where the Buddha is based. The guardians transporting the protagonists back to Chang'an drop them off abruptly at Heaven Reaching River, where the protagonists meet the turtle again. While ferrying the protagonists across the river, the turtle asks Tang Sanzang about the promise he made and the latter apologises for breaking his word. The unhappy turtle throws them off his back into the water and they swim to the shore. This incident fulfils the last of the 81 tribulations that Tang Sanzang is destined to face on his journey to obtain the real scriptures.