Knock knock. Who's there? Isadore.

Isadore who? Isadore a lock on this door, or is it just glued shut?

Knock knock. Who's there? Existential Crisis.

Existential Crisis who? I'm not really sure, because the concept of identity and self is fleeting and meaningless in an infinite universe.

Knock knock. Who's there? Alpaca.

Alpaca who? Alpaca the suitcase if you open the door!

Knock knock. Who's there? Leaf.

Leaf who? Leaf me alone, I'm busy!