2. Fill the back of the toilet bowl with vinegar and rub baking soda on the inside of the toilet. Wait.
3. Set up a talking tree in the bathtub in the middle of the night. They'll never forget to check behind the curtain again.
4. In the middle of the night take down all the Christmas decor and replace it with Spring.
5. Switch the name tags on gifts.
6. Wrap a present in multiple layers. Add a dead bug to one layer.
7. Make cookies with salt instead of sugar. Hand them out to people on the street.
8. Give a guy makeup.
9. Give a girl a guy's shaving kit.
10. Get an ornament that look exactly like someone's favorite. Break it.
11. Replace the nativity with aliens.
12. Say you're saving the best for last. Give a wrapped paint sample.
13. Put something really gross, like mustard in someone's stocking for them to stick their hand into.
14. Get up in the morning and act like it's not Christmas (as many people as you can get to play along, the better).
15. Lay next to the road in a Santa suit when a school bus goes by.
16. Go to the local mall and quote Buddy the Elf to the Santa. Sit on his lap, of course.