At work a friend of mine was bragging that his sister had to make his lunch for him. He was a pig that would eat anything. I put an H on a raw egg and put it in his lunch bucket. His poor sister probably got clean his lunch bucket. He did mention he never got eggs so he knew it was one of us.
I wonder if anyone has practical jokes they'd like to share, that they were involved in, as a perpetrator, or victim.
I once attempted to place an alarm clock in a friend's luggage, but he caught me. Just the thought breaks me up. That was 30 years ago, and now would be problematic on an airline. It was on a train though.