That orange is going to ruin the whole thing. He’s too bright and rotund to be out in plain sight without being noticed.
I can’t stand it when fruit keep knocking at my door, telling me to Witness the eternal benefits of vitamins and minerals. Now if it were bacon knocking at my door…
Haha, I am no longer a child either, but I am still going to buy this and wear it proudly. Never let go of your inner-child! 
They better hope that’s not the door of a vegetarian with an anger problem.
This was my favorite joke as a child. If a kid wanted me to tell a knock knock joke now, this would be my go-to joke.
I hope these guys knock on my door. Afterwards, I’ll be enjoying fruit smoothies for weeks.
This is the only knock-knock joke that my five year old knows - because it’s the only one that I know!
(Soooo tempted. I think my husband would kill me though, he hates hearing it overandoverandover.)
In for 1! 
This is the first Woot shirt that has made me laugh out loud when I saw it in a while. Awesome!
It was on i -think- seafoam when I first saw it up for votes at threadless. It looked real nice that way. But woot won’t increase their colors, so…
It’s probably behind the door.
Congrats Nathan. I’ve always found your illo of this joke to be charming.
That middle banana makes me feel… uncomfortable.
I don’t get it.
This shirt is quite clever.
Hmmm…smoothies.
>:D
Nice to see this printed, Nathan. Congrats!
Actually, I may now use this one. Very amusing.
Those bananas need to put some pants on!
One of my favorite woot shirts so far.
Of course, I enjoy corny humor.
Brings back great childhood memories…and “I don’t wanna grow up…I’m a Toys-R-Us kid”
I’ll wear the dang shirt!
Can’t resist meta-humor that even a 6-year-old can figure out! But navy blue in summer? I’m gonna roast for the sake of funny.
In for one. (Would get more for my 'netless friends & family if it weren’t so close to month’s end.)
Maybe you can use this one (from the movie Half-Nelson):
Knock-knock!
Who’s there?
Interrupting Cow.
Interrupti -
** MOO-OO-OO! **
Seems like it would please a five year old, anyway.