1: Tell the stoned that a major holiday is approaching in a few days time. Christmas is by far the best example. We did this to Josh in the middle to late part of November. I casually turned to him and said “Wow Josh, can you believe it? This is the last day of school before vacation!” His eyes got really big, and he goes “Really? Holy shit! That was fast, when’s Christmas? Isn’t it like in another month?” Chris goes “Uhh, no Josh, its Wednesday.” Josh freaked and went on this whole thing on how he hadn’t bought anyone presents and a whole other tirade on some weird stuff.
2: When the stoned is working, have you and a friend quietly, QUIETLY whisper his name. Our Geometry teacher had given us all sheets to work on, and Josh was working hard to do his. Chris and I looked at each other, and started going “Jooooooooosssshhhhh.” He would look up, get this weird, scared look in his eyes, glance around, and slowly go back to working. We did this to him three or four times. When we later commented on it to him, he goes “Damn! That was you two? I thought I was hearing things, I was freaked out.” Priceless.
3: Tap the stoned on the shoulder, and when they turn around, leap at them and go “Yaargh!” I can’t even tell you how funny this is. Make sure to space this Yaargh attacks out, so they’re special each and every time.
4. Get someone who can make funny/scary faces. Make sure the stoned watches. Do I need to say more?
5. Ok, this one takes a few circumstances you might not be able to recreate. Josh sits right in front of Chris, and I sit to their right, next to Chris. I could see outside the door, but those two couldn’t. We have Administrators patrolling our school during the day, to catch kids having sex, smoking, drinking, skipping, etc. One of them we lovingly named “Captain America”. Don’t ask, it was a tradition before I came to the school. Anyway, we heard people go by our door and I tap Josh and was like “Dude that was Captain America. He keeps walking back in forth in front of our door. If he comes in and asks you about anything, don’t worry, I’ve got your back.” Josh, of course, got scared as fuck. Chris, to add to the specialness of this, went to the door and came walking back quickly. He goes to Josh “Oh shit man; he said something about smelling marijuana. Don’t worry; we’ll stick up for you!” Captain America never did come in that day, but the look on Josh’s face was great.
There’s more but I cannot remember all of them right now. Rest assured I will add more as I figure more out.