I have very long hair, and many of my friends are against my cutting it. So, for one April Fools Eve, I emailed everyone that I had cut my hair right below my ears. When I saw several friends the next day, one of them tried to kill me. Just a little.
And a year or two ago, some friends and I made t-shirts with a picture of another friend from when he was 14. It was fun. he chased his brother (who smokes) because he thought said brother gave us the picture. The poor brother was wheezing and gasping for breath.
One prank I have always wanted to pull is to remove the ink from all pens in the vicinity. Don’t ask why, it’s just a dream of mine.