Knock Knock Jokes

Joke: Knock knock!
Who's there?
Interruption snail.
Interrupting snail who?
*10 seconds pass*
Snail!

Joke: Knock knock!
Who's there?
The interrupting pirate!
The Interr-
Arrrrrrrg you gonna let me in or not?

Joke: Knock knock!
Who's there?
Cows go!
Cows go who?
No, silly, cows go moo!

Joke: Knock knock!
Who's there?
Aardvark!
Aardvark who?
Aardvark a million miles, for one of your smiles.

Joke: Knock knock!
Who's there?
Ding dong!
Ding dong who?
Ding dong, I just found the doorbell.

Joke: Knock knock!
Who's there?
I.
I who?
Oh my gosh! The amnesia is worse that I thought!

Joke: Knock knock!
Who's there?
Doctor.
Doctor who?
I love that show.

Joke: Knock knock!
Who's there?
Repeat.
Repeat who?
Who who who who who, how long do I have to do this? Who who who...

Joke: Knock Knock!
Who's there?
I'm the interrupting doctor!
The interr-
You have cancer.

Joke: Knock knock!
Who's there?
Knock.
Knock who?
Knock knock!
Who's there?
Knock.
Knock who?
(Keep this going as long as you possibly can.)