Knock Knock!
Who's there?
Thermos.
Thermos who?
Thermos be a better knock knock joke than this!
Knock Knock!
Who's there?
Veal chop.
Veal chop who?
Veal chop around and see what bargains vee can pick up!
Knock Knock!
Who's there?
Foster.
Foster who?
Foster than a speeding bullet!
Knock Knock!
Who's there?
Sherwood.
Sherwood who?
Sherwood like to meet you!