Luke's Knock Knock Joke

This is Luke's signature joke. 

He made it up a while ago and it's always his go to when he wants to get a laugh. Sometimes it's a little louder with a little more emphasis, yet it never seems to disappoint. I think it's the simplicity. ;)

Knock, knock
Who's there?
Honk
Honk who?
HOOOONNNNK!