I got this idea off of a topic on tv.com, but most of the jokes are original :P

Yo mamma so fat, it takes Nathan a week to fly around her

You mamma so fat D.L. cant phase through her

You mamma so fat Hiro broke his powers trying to bend the space around her

Yo mamma so stupid Sylar tried to take her brain but didnt find anything

Yo mamma so fat Isaac ran out of paints trying to paint her future

I hope you liked them :P