1. Flesh eating bacteria doesn't sound like a cake walk. And there's no healing from it. It eats your flesh.
2. spiders crawling in my mouth while I'm sleeping. I heard a statistic once that over the span of a lifetime, the average person swallows around 8 spiders without realizing it.
3. really really sharp objects like scalpels. The kind that could slikce your finger down to the bone before you even felt it.
4. Rattlesnakes. I've had dreams where I feel the force of the bite hitting my calves. My legs swell up and turn all blue-black.
5. Any type of crushing or ripping genital injuries. Just not the type of thing I would ever want to experience. To make things worse, there are people who are actually into mutillating themselves. Never ever send me any pictures of that type of thing. It makes me convulse.