Knock Knock Who's there? Muffikin Muffikin who? Muffikin fingers are trapped in the door.
Knock Knock! Who's there? Zany Zany who? Zany body home?
"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? Allahu Akbar. Allahu AK- BOOM!!!
Knock knock. Who's there? The interrupting cow. Interrupting cow wh- Moooooo!
Knock Knock. Who's There? Justin. Justin who? Your justin time to wipe my ass!
Knock knock. Who's there? Hatch. Hatch who? Bless you.
Knock, knock; Who is there? Love; Love who? U, U, U!
Knock knock. Who's there? Sarah. Sarah who? Sarah problem here?
"Knock, knock.Who's there?" very long pause... "Java."