Knock knock. Who's there? Maple.

Maple who? Maple you a favor and open the door!

Knock knock. Who's there? Egg

Egg who? Egg-cuse me, I'm cracking under the pressure to make a good pun.

Knock knock. Who's there? Existential Crisis.

Existential Crisis who? I'm not sure, I've been questioning the meaning of my own existence and the nature of identity, so the concept of a 'who' is somewhat fluid to me.

Knock knock. Who's there? Pane

Pane who? I'm glass you're excited to meet me, but I'm a little transparent about my feelings.