Zhang He
When Yuan Shao heard that Wuchao was under attack, he sent his generals Zhang He and Gao Lan (高覽) to attack Cao Cao's main camp in the hope of diverting Cao's attention away from Wuchao. However, Zhang He and Gao Lan, already frustrated with Yuan Shao, ended up defecting to Cao Cao's side instead. They destroyed their own camps and led their men to Cao Cao's main camp to surrender. Cao Hong was initially suspicious about Zhang He and Gao Lan, but Xun You managed to convince him to accept their surrender.