There is a comprehensive list of funny "your momma" jokes on Jokes4us.com. The website features a variety of all types of jokes, including a link to "yo mama" jokes on the menu.
There are fun variations of "yo mama" jokes, including, "yo mama so bald," "yo mama so fat," "yo mama so stupid" and "yo mama so ugly." For example, "Yo mama so bald, you can see what's on her mind" or, "Yo mama so fat, I ran out of gas trying to drive around her." This website even features a "Yo mama joke generator," in which a click instantly creates a random "yo mama" joke.