This practical joke is only for the professional pranker. I was a card-carrying member a few years back (click here to read the story), and this one here calls for some serious commitment and a strong stomach.

The first time I heard of this prank being pulled, the "puller" was, believe it or not, George Clooney. This joke is meant for anyone who has cats. If you have a feline in your household, any family member can be fooled. But, I'd prefer to hear that you pulled this off at someone else's house. Extra points if you do! Or in this case, do-do!
How you go about setting this up is completely your choosing. When nobody is looking, you need to place a massive "Tootsie Roll" in the cat's litter box! And I'm not talking about the candy inside a lollipop.  That's right...only the real thing will work. Whether you "prep" ahead of time and bring it in a baggie, or hope that nature will take its course when you're ready, either will stun the cat's owner when you point out what Jingles just did in his litter box! Now, to complete this prank, you can NEVER let them know it was you. They may suspect it, but the stories will grow with each telling.