My "hilarious" friends, thinking back on that old chemistry trick of setting fire to money, tried to mixed alcohol with water and set fire to my trousers.
All was well, since I was wearing thick jeans and am a light sleeper, allowing me to put the flames out before any damage was done, but even so- waking up actually on fire is fucking frightening.
Same friends - woke up once while camping a night in the country, they'd tied my leg to a broken car door we'd found the night before, and opened the farm gate just next to our tent area. Woke up being screamed at by a fuck-off angry goose that my friends had chased towards me (I was outside the tent, it had been a hot night), massively hungover, and found movement significantly impeded.
It's part of our culture though, these pranks. I once saw a guy carefully zipped up in his sleeping bag and placed at the top of a flight of stairs lined with mattresses, cushions, duvets etc. He was deposited at high speed down this makeshift slide. His scream of terror as he awoke mid-descent was a beautiful thing to behold.
Another notable one happened at a party I missed, but a couple of guys picked up a drunken sleeping friend, tied him up with packing tape, put him in the back of the piece-of-shit car one of them had brought. He wakes up as daylight hits him, tied up, cold, in the back of a moving vehicle, driven by two men wearing skimasks.
Apparently he didn't take long to spot the jig, but a frightening few moments there as his befuddled, hungover brain desperately tries to piece together its surroundings.