But practical jokes just make people feel bad. They don't do anything except make you laugh for two minutes and the person it's played on hates you for days weeks or months.
Adding to knight_34's list, it causes trouble. But, if they're harmless, I found this funny one.
Meet someone you know in the school hall, talk with them, then say goodbye and let them walk away from you. When this person is a good distance from you, call them back (as if you have a secret to tell them, so they have to get close to you again). When this person gets back to you, lean over and whisper in their ear, "How far would you have gotten if I hadn't called you back?!?!"
back in elementary school i put lined up ketchup packets under the toliet seat and when my friend had to crap (or maybe pee idk) he sat down and ketchup squirted loool
Uh.... I don't do jokes, but I seen someone did something.
Someone in my class stuck a pencil, but cuted it, so the teacher can see that he stuck it through, and in his ear, is a ketchup packet, so he stabbed it so the ketchup (as blood) came, and it was funny, the kid got detention, but the teacher somehow passed out.
lol im not sure if this counts. one time i told my friend that im going to a specific city to find an apartment so we can move there (i just went to vacation). meanwhile when i was relaxing he told that to his friend who told it to our teacher so when i came back it was like
teacher: we know why you went to that city. we will really miss you. me: ............ (remembering) oh yeah... its ok i think we will stay here anyway.
lol i dont know what id do if they made me a surprise party XD all i wanted was to fool my friend on april fools. i didnt want to fool my whole class XP
One time, I saw the phone number of someone on his car, called it once a day and left a blank message for one month. If he picked up, I would breathe heavily and say, "They're coming for you" and then he finally disconnected his phone. Pretty funny.