The biggest snake that bit me was my retic. She was about 9.5'-10' at the time, back in December. Our power went out, and I was panicking a bit so I wasn't thinking as clearly as I usually would. :/ Instead of getting River out first, I left her till last. Well, between me moving back and forth picking up snakes and bagging them up, it was working her up into food mode. On top of that, I didn't realize that the duffel bag I was going to put her in was soaked in cat urine smell. I didn't spend enough time with the hook getting her out, and she grabbed my hand, no wrap. I got my SO to try to tap her face to get her to let go, and she just dug in deeper and started to pull my hand into the enclosure. I took the tongs from him and tapped her teeth myself and she immediately let go and pulled back into her enclosure. My hand was swollen pretty bad and stung a lot, I couldn't pick up anything with that hand for a day or two and it took a few weeks for the scabs and bruises to heal. It left a little bump on my finger joint for a few months, too, but no lasting damage of any sort, and that bump is now gone.

Some of the other bites in this thread is why I usually remove my snakes from their enclosure before cleaning up, even if it's just to change water or pick up poop. If I trust them, and they're hidden, I'll chance it, but I never trust my more food oriented bebs, like River, Howl, and Crona. Nowadays I also close the doors on my tongs so the snake can't get to me even if they miss - love sliding glass doors, they feel a lot safer than I image swing doors could be.