From 《
史记·
孟尝君列传》: when Lord Mengchang (
孟尝君) of Qi was detained by King Zhao of Qin, one of his retainers sneaked into the palace like a dog to steal back a fox-fur robe as a bribe, while another imitated a rooster's crow at the pass gate, tricking the guards into opening it early. The 'petty' skills saved their lives.