Why can Niu Wangmo fool the Monkey King?

The Monkey King's vigilance is not too high, and he believed Bajie easily, but he was cheated by Niu Wangmo.

Back to 6 1: Zhu Bajie helped defeat the demon king, and the Monkey King tuned the banana fan in three tones.

Niu Wangmo turned into a pig and took over the fan. Sanxiang was fighting with Wukong. With the help of the protector, Niu Wangmo failed. Zhu Jin and Tian Bing subdued the cattle.

The Monkey King borrowed a fan from Princess Iron Fan, and Princess Iron Fan flew to the Monkey King with the fan. The Monkey King turned into a bug and threw it into the belly of Princess Iron Fan. Princess Iron Fan gave a fake fan.

The Monkey King became a true fan cheated by Niu Wangmo, and Niu Wangmo became a true fan cheated by Zhu Bajie. When the Monkey King was shooting cattle, Princess Tiefan lent a banana fan, the Monkey King fanned out the Flame Mountain, and Tang Priest and his disciples went west.

Extended data:

Tang Priest and his disciples went to the Western Heaven to learn Buddhist scriptures. Flame Mountain is the only way. The flaming mountain is very big, not just any fire. Only the banana fan can be put out. Banana fan is the treasure of Princess Iron Fan. The Monkey King borrowed a fan from Princess Iron Fan for the first time. Princess Iron Fan flew to the Monkey King with a fan, and the Monkey King turned into a bug and threw it into her stomach. Princess Iron Fan gave her a fake fan.

The Monkey King became a true fan cheated by Niu Wangmo, and Niu Wangmo became a true fan cheated by Zhu Bajie. When the Monkey King was shooting cattle, Princess Tiefan lent a banana fan, the Monkey King fanned out the Flame Mountain, and Tang Priest and his disciples went west.