Can i say this as an original Knock Knock joke?

This is, I hope, an original joke.
If its not, then am sure I'll find out in seconds after posting.
It doesn't really work on the page, but verbally to someone else I think its ace, as it splits your friends into those who get it instantly and those who really don't.. and they often repeat the 'whose there?" reply creating a mini repeat game.. it is funny to see how many times you can take it round before they eventually get it or give up in confusion.
ok.. so.. most definitely a bigger build up than this simple little joke deserves.. so here here it is reddit..

Knock Knock.
Whose there?
Woodpecker!
Woodpecker who?
KnockKnock.