This was on St. Patrick's day, but it would make a good April Fool's, too depending on how drastic you want to get...

My dad got off work really early in the morning and bought us some green cookies and died a gallon of milk green. Then, he noticed he still had a ton food coloring. He snuck up and wiped it on all of our faces. I woke up in the middle of it and said "What are you doing?" And he said "Oh, you had sweat all over your face so I'm wiping it off for you my baby" (Okay my dad *NEVER* would have done something like that, nor would he have spoken tenderly like that unless he was up to something but I was too tired to realize this). So we wake up in the morning and one by one we see eachother's faces and laugh at eachother, then realizations hits and we each dart to the bathroom to behold our completely green faces. Now food coloring doesn't wash off of faces very easily ya know??? And we had to go to school with traces of the green still on us!

That's a fun memory (even though I got totally DUPED!)