Climb a tree at 2 in the morning, and bring a harmonica. When someone walks by, start playing.
Prank your friend by saying, "I will get you anything you want, I'm a millionaire from today on!" They will tell you. Say "I'll bring it tomorrow." The next day give them a piece of paper with the thing the asked for drawn on it!
Go to the beach, in the middle of the summer, wearing a Santa costume, and bring a boom box so you can dance to carols!
At school on a casual clothes day bring a spare set of clothes and change in the middle of the day (Bonus: Swap clothes with a friend).
Empty out a bleach bottle and refill it with milk. Carry it around and drink from it . For best effect, bring a cup along too.
Clean out a mayonnaise bottle and replace it with yogurt. Then, bring it to lunch at school and start eating it.
Buy a donald trump mask online and go to a public place wearing it with something a president would wear. Bring a friend with you who has a hillary mask and outfit on. Have a fake fight with eachother. See who notices.
Pretend to be a dog and bring peoples newpapers to their door. Ring the doorbell when they open wag you tail and stick your tongue out.
Bring a chair into the elevator and a few books and stay there and read. Bring some coffee too.
Call a stranger and say, "My dream is not a dream, for I will make it a reality. I will bring unicorns back!" in your most serious voice
Have a better idea for this list? Send it on in!