Related:

• (knock, knock) "Who's there?" "A polish thief.
• Knock, knock. Who's there? Gladys. Gladys who? Gladys Thanksgiving. Aren't you?
• Knock, knock. Who's there? Death. Death wh..........
• Knock, knock. Who's there? Waddle. Waddle who? Waddle I do if you don't open the door?
• Knock, Knock S. Hussein: "Who's there?" KA S.
  H. "Ka who? " KA_BOOM!!!!!...
• Knock, knock." "Who's there?" "Oz." "Oz, who?" "Oz be the new mayor!
• Knock, knock. Who's there? Harry. Harry who? Harry up, I'm hungry!
• Knock knock Who's there? Little old lady Little old lady who?
  Gee, I didn't know you knew how to yodel....
• Boss: (to employee) - Experts say humor on the job relieves tension in this time of down-sizing, Knock, Knock.
  Employee: Who's there? Boss: Not you anymore....