Knock knock. Who's there? Maple.

Maple who? Maple syrup to talk to you, I've been feeling a little stuck.

Knock knock. Who's there? Lettuce.

Lettuce who? Lettuce in, and we'll 'romaine' here all night, serving up 'head'-spinning puns until you 'leaf' feeling 'crisp' with laughter!

Knock knock. Who's there? Cows go

Cows go who? No, cows go 'moo'

Knock knock. Who's there? Wanda.

Wanda who? Wanda why you won't open the door!