仇人姓大名姨妈
[chóu rén xìng dà míng yí mā]
The phrase combines the Chinese word for aunt (姨妈) with an ironic twist on the surname 'Big'. The intended humor lies in a satirical approach to addressing a significant grudge using family-like language which could lighten some of the weight or express a peculiar sense of familiarity towards the antagonist.