I don't ever do April Fools jokes. When I was around 10 years old, I was hanging outside with my friend in front of his house. One of our friends' sister came out from the house next door and said she needed help real quick because our friend's dog was hurt. We started to walk and I sort of stopped, "Dude, it's an April Fools joke."
Then she started crying. And I was like, "Woah, serious." So we went out in the backyard and the dog had choked itself to death on its chain when it tried to jump over something. We untangled it but it was too late.
tl;dr Bad stuff happened on April Fools once, so I don't do any jokes.