Wu Anguo 武安國

Wu Anguo is a fictional character, created by Luo Guanzhong, who appears in the novel Romance of the Three Kingdoms and various Three Kingdoms games by Koei.

Biography
During the Battle of Hu Lao Gate he challenged Lü Bu to a duel. Equipped with an iron hammer, he fought several dozen matches, but his arm was chopped off and he fled, leaving behind his iron hammer.