Knock knock! Who's there? Yah! Yah who? Naaah, bro, I prefer google.
Knock-knock. Who's there? To. To who? No, to whom.
Chuck Norris was once part of a knock knock joke. The Joke ended abruptly when after the first knock the door blew up killing the man behind it.
Knock, Knock! Who's there? D umbbell. Dumbbell who? Dumbbell doesn't work so I had to knock!
"Have you heard my knock-knock joke?" asked the blonde. "No," said the brunette. "Okay," said the blonde, "you start."
Knock Knock. Who's There? Justin. Justin who? Your justin time to wipe my ass!
Knock, Knock! Who's there? Doctor Doctor who? That's a great TV show, isn't it?
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