Yan Dahai in "Hero of Rat Gallbladder" gave people the feeling of being a coward at first, but later became a real hero. Yan Dahai was originally the younger brother of the Qinglong gang. Although he is also a strong man with a dragon and a tiger, he is weak. He has always liked Du Qing, the singer of "Philemon". In an accident, Yan Dahai was diagnosed with terminal cancer, and his life was only three months. During these three months, he decided to do something he had never done before, one of which was to confess to Du Qing.

Because he went to Du Qing to confess, Yan Dahai overheard that Du Qing owed a loan shark of 50,000 yuan, and he decided to help Du Qing pay his debts himself. But even if he bought a house and all his possessions, Yan Dahai failed to collect so much money. It was just an accidental opportunity. He sneaked into the police station and killed the undercover of the Axes by mistake, making Yan Dahai a policeman. At first, Yan Dahai only came to sacrifice his pension, but he wanted to die, but he couldn't. He also makes contributions every time, and Yan Dahai, who is more and more admired by the people, gradually looks like a real policeman.

Because he tried to die again and again, he was involved in Yan pattern. After Yan Dahai killed Zheshou, a Japanese Yantu businessman, he found that the biggest behind-the-scenes figure behind the Yantu transaction turned out to be the police chief. When Yan Haihe came to Feilemen to look for the stolen goods hidden by Zhou, they had a fight. In the process of fighting, Yan Dahai knew that the diamond was on the chandelier of Feilemen, but in the end he drowned in a fish tank with Zhou. No one in this world knew the secret.

At the end of the movie, Du Qing found many diamonds under the small fish tank, which made many people doubt that Yan Dahai was not dead. This design may be to make up for the audience's regret about Yan Dahai's death, because he did die in a fish tank, and the people still regard him as a breeder. Finally, diamonds may appear to echo the setting of hades. Even though Yan Dahai died, he still guarded Du Qing.