Knock knock. Who's there? Isabelle.

Isabelle who? Isabelle necessary, or can I just walk right in?

Knock knock. Who's there? Sew

Sew who? Sew long, I've been trying to stitch together a decent joke.

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? Otto B.

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