I was at a friends house around Halloween and we decided to dress up in Metro 2033 get-ups. I bought about 25 of these smoke balls and I tied them all together and lit the fuse and threw them in his room at around 2am so he woke up with his room full of smoke and saw me wearing my costume ( Yes, it had a gas mask... ) with an Airsoft rifle and he flipped the stuff out. He almost called the cops but I told him it was a prank and he gave me a good kick to the shin and we had to open his windows, turn on his fan, and about 2 desk fans to get the smoke out of his room
I pranked my friend by wearing combat gear while his room was full of smoke and he almost called the cops at 2am