《搜神后记·卷九》
那奴仆越来越急切地催促张然快吃完饭，张然决定，用手猛拍大腿大声呼喊道： 乌龙出手！ 那狗应声扑了上去咬伤奴仆，奴仆丢掉武器倒在地上，那狗咬掉奴仆的生殖器，张然因此拿起刀来杀死了奴仆。
奴催食转急。然决计，拍膝大呼曰： 乌龙与手！ 狗应声伤奴。奴失刀仗倒地，狗咋其阴，然因取刀杀奴。
The servant urged Zhang Ran to finish his meal more and more anxiously. Zhang Ran decided to pat his thigh and shout, "Black Dragon, attack!" The dog jumped up at the sound and bit the servant. The servant dropped his weapon and fell to the ground. The dog bit off the servant's genitals, and Zhang Ran took up a knife and killed the servant.