Anti-jokes are jokes that are funny because they're not . . . here are some examples:
Why did the chicken cross the road? To get to the other side Why did the monkey fall out of the tree? Because it was dead. Why did sally drop her ice cream? Because she got hit by a truck. Whats red and smells like blue paint? Red paint.
If you still don't get what they are search it up on Wikipedia Add your owns below =D
I find this one funny which I heard in a movie "An Irish man tried to blow up a car but burned his lips off exhaust pipe" (Still dont know why it was an Irish, not a scott or english?)