Knock knock. Who's there? Alpaca.

Alpaca who? Alpaca the bags, we're going on vacation!

Knock knock. Who's there? Fig

Fig who? Fig-ure it out yourself, I'm busy!

Knock knock. Who's there? Maple.

Maple who? Maple syrup to talk to someone, I'm feeling a little drained.

Knock knock. Who's there? Cows go

Cows go who? No, cows go 'moo'