Knock knock. Who's there? Ego.

Ego who? Eggoing to let me in, or is that just a waffle excuse?

Knock knock. Who's there? Otto B.

Otto B. who? Otto B. a crime if you didn't laugh at that groan-worthy pun!

Knock knock. Who's there? Flour.

Flour who? I knead to talk to you.

Knock knock. Who's there? Parenthesis.