Toilet prank 1: A real classic. Place cling film (plastic wrap) over the toilet seat. Your victim won't see it until it is too late!
Toilet prank 2: A modern twist. A horrible monster that hides inside the toilet bowl, waiting for your unsuspecting victim!
Toilet prank 3: Place a thin layer of vaseline in patches around the toilet seat. It is barely visible but your victim will certainly feel it - they won't know what it is.
Toilet prank 4: Use a prank explosion to scare your victim when they are on the loo.
Toilet prank 5: Use about two or three packets of powdered jello (jelly) and mix it gently into the water in the bottom of the pan. It will take quite a few hours (up to 24) but if you can find a time when you know the toilet won't be used for a while, then the wait is worth it. Eventually the jello will set. You can imagine your victim's attempts to flush their poo away! Green jello works best for that visual effect.
Toilet prank 7: Barbed wire toilet paper.
Toilet prank 8: Swap the signs. Many toilet signs are only lightly glued or even just slide into a holder on the door. They are easy to swap over! Alternatively print out your own toilet signs to put on office doors.