Years ago I had a large male Eastern that I had raised from a hatchling. All the years I had him, he never showed any aggression or any inclination to bite..he was dog-tame. One day I was showing him to some non-herper friends (you know the type..."How can you keep those creepy things, don't you have nightmares? Aren't you afraid one will get out?"
. I was explaining how docile he was and how he had never bitten anyone or even tried to, and that it was perfectly safe to hold him. Just when I just about had them converted (in my mind, anyway) he calmly turned his head and clamped down on my left thumb...HARD, and started gnawing. All I could do was wait for him to finish. I suppose it goes without saying that my friends left unconvinced that snake-keeping was a safe hobby. That was, without a doubt, the most painful non-venomous bite I've ever experienced. My thumb bled for hours.
The only other colubrid that came close was a big Mangrove Snake that got the pad of my left index finger in those rear fangs and chewed for a bit. The Mangrove Snake incident was 20 years ago, a fresh import from Thailand that I had just picked up in a shipment of probably 70 or 80 animals at the New Orleans International Airport. I wasn't even sure what was in the bag when I opened it because it wasn't marked (half the time in those days they weren't). I learned a lesson from that one. It could have just as easily been a big Monacled Cobra or Russel's Viper or something like that. When I opened that bag, that snake came out of there like a rocket right at my face, mouth open looking for something to bite. I clamped the bag around him mid-body with my hands and then tried to grab him behind the head. That's when it turned ugly. At any rate, that was another VERY painful bite from a "harmless" snake.
I still have scars from both of those bites.