Knock, knock.
Who's there?
Banana.
Banana who?
Orange.
Orange who?
Orange you glad I didn't say banana again?
Bob has no arms.
Knock, knock.
"Who's there?"
"It's not Bob."
Knock, knock.
Who's there?
Spell.
Spell who?
W. H. O.
Knock knock.
Who's there?
Dyslexic.
Dyslexic who?
You.
Why did the chicken cross the road? To visit the idiot.
Knock knock.
Who's there?
The chicken.
The chicken who?
*Silence*
Knock, knock.
Who's there?
Bum.
Bum who?
Bum holding a pistol!
Knock knock.
Who's there?
Police.
Police who?
Police stop telling these awful knock knock jokes!
Cock cock, who's there? Nobody.