Handsome, brave, clever and charismatic, Bai Yutang is the youngest sworn brother and the best fighter of the "Five Rats", whose other members are Lu Fang, Han Zhang, Xu Qing, and Jiang Ping. Though very righteous, he is also cruel, arrogant, reckless and stubborn. After fellow knight-errant Zhan Zhao receives the title "Imperial Cat" from the emperor, Bai Yutang becomes jealous and hurries off to the capital Kaifeng to challenge him. Using his extraordinary martial arts skills to intrude into respectively the government headquarters of Prefect Bao, the residence of Imperial Tutor Pang, and even the imperial palace, he performs a number of spectacular acts and crimes. He also succeeds in capturing Zhan in a trap, but is in turn captured by his sworn brother Jiang Ping, after which he reluctantly submits to the government. The emperor forgives his many crimes and assigns him to assist his sworn brother Judge Yan Chasan (顏查散) to foil Prince of Xiangyang's (襄陽王) rebellion. Overconfident in his abilities, Bai heedlessly ventures into the prince's deadly Sky-Scraping Tower and suffers a tragic death in the Brass Net Trap.