Earlier days of shift work. One guy on afternoon and night shifts would simply steal peoples food from the fridge. You would get back to find your container with just chicken bones or empty sandwich wrappers. The guy was a fucking pig. Even when caught we continued doing it
Plan formulated for next night shift . One of the girls came in with a beatifully crafted birthday cake. She must have been pissed at him. Liquid laxative in the cake. Chocolate Laxative in the icing and Laxative Chocolate buttons as decorations. Everyone gets a small slice and just before we can all "enjoy" our birthday cake an emergency call is received. Everyone runs out leaving said pig with the cake.
By our reckoning he ate about a third of the cake. Though he claimed the peices fell on the ground when he was putting the cake back in the bridge for everyone
Came back 2 days later looking at little paler and thinner. The fat bastard ate the rest of the cake when no one was around!