Knock, knock. Who's there? Kanga. Kanga who? Actually, it's kangaroo!
Knock, knock. Who's there? Owls say. Owls say who? Yep, that they do.
One day a man heard knocking at his door. He opened the door only to see a small snail sitting there smiling. The guy picked the snail up and threw it as far as he possibly could. Three years later he heard knocking at the door again. He opened the door to see the snail. The snail said, "What the hell was that all about?"
What did the bunny want to do when he grew up? Join the Hare Force.
Knock Knock! Who's there? Zany Zany who? Zany body home?
Knock knock. Who's there? Allahu Akbar. Allahu AK- BOOM!!!
"Have you heard my knock-knock joke?" asked the blonde. "No," said the brunette. "Okay," said the blonde, "you start."
What South American dance do cows like to do? The Rump-a.
Chuck Norris doesn't get shark attacked, the shark gets Chuck Norris attacked.
If you had fifteen cows and five goats what would you have? Plenty of milk.