I got stung by a ton of paper wasps when I was three.
Me and my brother went to a junkyard with my father. While they were staring at something, I was just standing there, no worries. Then I notice a paper wasp nest right at eye level, under a table. One wasp comes out, and starts flying near me. Then a few more come out. I start saying "Daaaad... Daaaaaad...", he just replies with "Hold on a second, Alex.". I flinched out of fear and all the wasps attack my face. Then, basically the whole loving nest full of them comes out and joins in. I blacked out for a while, and I woke up to being carried by my father while he was running to the car.
Most terrifying four minutes of my life.