Knock knock. Who's there? Cereal

Cereal who? Cereal-ly good at making bad jokes, it's a grain of truth!

Knock knock. Who's there? Alpaca.

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

Knock knock. Who's there? You tell me.

You tell me who? No, *you* tell *me* who's there. I'm the one knocking, how should I know who's inside?

Knock knock. Who's there? Don't ask.

Don't ask who? Exactly.