Mother Insult

Used as an insult, "your mother..." preys on widespread sentiments of filial piety, making the insult particularly and globally offensive. "Your mother" can be combined with most types of insults, although suggestions of promiscuity are particularly common. Insults based on obesity, age, poverty, poor hygiene, unattractiveness, or stupidity may also be used.

Also, was Shakespeare the original T-Dog Jenkins?

http://en.wikipedia.org/wiki/Yo_Mamma

dirty dozens