Knock knock. Who's there? Alpaca.

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

Knock knock. Who's there? Silence.

Knock knock. Who's there? Hearse.

Hearse who? Hearse a real groaner for ya: I used to be a baker, but I couldn't make enough dough to roll with the big timers!

Knock knock. Who's there? Silence.