Crap In The Reserve Tank
Open the reserve lid of the toilet and take a crap inside. The poo may float around in there for a long time before someone notices.

Colorful Bathroom Sink Water
Fill your victim's bathroom sink all the way to the brim. Clog the reserve drain. Then add some food coloring to the water.

Porta Potty Fun
While your victim is inside a porta potty, slowly tip it over on the door side. Now the door is facing the ground and he or she cannot get out. On top of that, piss and feces has now spilled out all over him or her.

Bathroom Stink Bomb
Drop a stink bomb in any public restroom after you are done taking a crap. It will make everyone think your crap is the worst smelling ever!

Restroom Hand Dryer Prank
Flip the open part of an automatic hand dryer up and pour some dye powder inside. Make sure to get it deep inside the little heater part. Now flip it back down while holding a napkin up to catch any loose powder. The next person to use the hand dryer will end up with dirtier hands than before he washed them with water.

Poo On The Toilet Handle
Smear some melted chocolate on the toilet handle in a public restroom. Everyone will think its poo instead of chocolate and will try to avoid flushing it.

Watergun In The Bathroom
Randomly walk up to people using the urinals at a public restroom and squirt them with a water gun. They will not be able to do anything about it until they are done pissing. This give you plenty of time to escape and run like a mad man.

Soggy Toilet Paper Prank
In a public restroom, unroll some toilet paper and get it soggy with some water from the faucet. Then toss it up so it sticks to the ceiling. Do this a few times if you would like. After awhile they will fall to the ground. If your prank goes as planned, Someone else will be in the restroom at that time and it will fall on their head.

Porta Potty Unscrew
While your victim is using a porta potty quickly unscrew all four walls so they drop to the ground.

Pop The Balloon
Use a funnel to put some poo inside a balloon, then blow it up, tie it and tape it the inside stall wall of a public restroom. Next, tape a stick or pin to the stall as well. Along with a note that reads, "Pop this balloon for a special surprise inside." Then go back in a few hours and see if anyone popped it.