"Baihu" was not Yan's real name, but a nickname given to him due to his physical prowess or skin colour; thus his name should be translated as "White Tiger Yan". According to the Records of the Three Kingdoms, Yan Baihu held gigantic influence among the Shanyue tribes and even Han officials in the Wu area. When Liu Yao was appointed as Governor of Yang Province, he approached Yan Baihu to bribe him for support against the warlord Yuan Shu, who had a large army in the Huai River valley.
After the warlord Sun Ce defeated Liu Yao at the beginning of a series of conquests in the Jiangdong region, Yan Baihu successfully re-established or even increased his private army to tens of thousands, composed of elite Shanyue people and bandits, to prepare a final showdown with Sun Ce. Besides being the head of a loose confederation of bandits and local officials, Yan Baihu formed an alliance with another warlord, Wang Lang, who had enough provisions to account for all of the alliance's soldiers.
Despite Yan Baihu's preparations, Sun Ce was able to outwit Wang Lang and took his supply base through tactics; with no supplies, Yan Baihu and Wang Lang were easily defeated by Sun Ce. Yan Baihu then fled into the hills, where he continued to encourage the Shanyue people to oppose Sun Ce's rule over the Jiangdong territories.
In the 14th-century historical novel Romance of the Three Kingdoms, Yan Baihu was attacked by Sun Ce and then fled to Wang Lang to seek help. While seeking the aid of Wang Lang, however, his army was defeated by Ling Cao and his son, Ling Tong. During Yan Baihu's retreat, Dong Xi caught up with him and slew him. Dong Xi then sent Yan Baihu's head in a box to Sun Ce.
Historically, it was likely that Yan Baihu was defeated by Sun Ce's vanguard Ling Cao, however, he did survive the rout, and at least lived up to the time of Sun Ce's death.
... Xu Gong was defeated and took refuge with White Tiger Yan, and Zhu Zhi took over the office of Grand Administrator...