The boomslang, found in the jungles of sub-Saharan Africa, is actually fairly tame. That being said, few who have been bitten by this unassuming snake have lived to tell the tale, so if you come across one, play nice.
Because of the boomslang's shy, docile nature, most believed that it wasn't venomous at all.
Scientists classified it as "chill" (not really, but you get the idea).
But in 1957, a herpetologist working for the Chicago Zoo by the name of Karl P. Schmidt got nicked by a single fang and became the creature's first recorded victim.
The fact that he was bitten is impressive considering the snake has to open its mouth 170 degrees to hurt anyone. Schmiddy must have really pissed that one off.
The venom doesn't kick in until several hours after contact. Symptoms start with nausea and headaches. Then the venom attacks red blood cells, inhibiting the blood's ability to clot. Finally, blood pours out of the mouth, nose, anus, and even the eyes.
I believe the scientific term for that is "gross."
Schmidt completely changed the perception of the boomslang, which is now considered one of the most venomous snakes in Africa. Luckily only 10 people have met Schmidt's fate.
The good news is that if you get bitten by the boomslang, you have some time to seek medical attention before you start looking like a heavy metal band's newest album cover. The bad news is that if you don't have the medicine you need, it's a long and painful death.