Trapped in a dragon, unable to get out.

The original meaning is that the dragon is trapped in the middle reaches of shallow water, which can be compared to a person losing power.

Source: Ming dynasty's anonymous "Zengguang Xianwen": Longyou shallow water was played by shrimp, and the tiger fell to Pingyang and was bullied by dogs. I learned that cats are not as good as tigers and chickens are not as good as chickens.

Dragon swam in shallow water, teased by shrimp, tiger descended to Pingyang, and bullied by dogs. The valued cat is fiercer than the tiger, and the phoenix can't compare with the chicken when it loses all its hair. Metaphor means that after losing power and influence, a person is oppressed by the weak.