In fact, there are many monsters that the Monkey King can't beat, but these monsters the Monkey King can't beat at all, because these monsters all have strong backgrounds, such as Hong Haier, who eventually became a boy next to Guanyin Bodhisattva. I believe I don't need to say that everyone knows that Guanyin Bodhisattva in Nanhai is powerful. If the Monkey King hits Hong Haier casually, it is equivalent to losing face to Guanyin Bodhisattva, and the mount under Guanyin Bodhisattva's seat was once a demon. This the Monkey King can't fight, and there are many similar situations, so the monster in Journey to the West doesn't mean that he can fight by fighting. Of course, in addition to this main reason, there may be the following reasons:

1, the Monkey King really can't beat it.

Although the Monkey King works miracles, some monsters, especially those with special abilities, can't beat the Monkey King. For example, Hong Haier mentioned above is of this type, and Hong Haier's three flavors of real fire can be said to be quite powerful, which is beyond the competitiveness of the Monkey King. When encountering this kind of monster, the Monkey King can only call for reinforcements, such as Guanyin Bodhisattva, which can easily kill Hon Hai.

2. The devil's magic weapon is too powerful.

Sometimes the monster itself can't beat the Monkey King, but some magic weapons held by the monster are really too powerful. These magic weapons have been tempered for thousands of years when some immortals keep them. After being smuggled out by these monsters, the Monkey King actually had no choice. For example, when playing King Jinjiao and King Yinjiao, the gourd in their hands is not controlled by the Monkey King.

The Monkey King did it on purpose.

There are some monsters that the Monkey King deliberately didn't kill, because in the original Journey to the West, there were many times when the Monkey King and Tang Priest disagreed. The Monkey King also wanted to take this opportunity to beat Tang Priest or Pig Bajie, which meant to tell them, "I am responsible for killing monsters, but in the end, Master is ungrateful. You must understand this in your heart, or I will quit. "