Knock knock. Who's there? Ivan.

Ivan who? Ivan telling you to open this door for ages, my knuckles are practically knocking themselves!

Knock knock. Who's there? Fig.

Fig who? Fig-ure it out yourself, I'm busy!

Knock knock. Who's there? Homer.

Homer who? Homer-ly, who could resist a classic like this? It's an *epic* pun, don't you think?

Knock knock. Who's there? Otto B.

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