Knock knock. Who's there? Cows go.

Cows go who? No, cows go 'moo'.

Knock knock. Who's there? Marmalade.

Marmalade who? Ma'am, I'd like to spread some cheer with a joke that's jam-packed with puns!

Knock knock. Who's there? Alpaca.

Alpaca who? Alpaca the suitcase, you load the car!

Knock knock. Who's there? Dew.

Dew who? Dew-n't worry, it's just a drop in.