Hey so snakes that inject venom into the bloodstream are pretty bad, how about a snake that injects venom into your bloodstream AND makes you bleed out from every orifice? Sound good?
The boomslang (Dispholidus typus) is a venomous tree snake native to Sub-Saharan Africa. Blunt-faced and pretty, with relatively enormous eyes and a bright, light green colour in males and brown in females, the boomslang spends its days up in the trees, hunting for lizards, frogs, chameleons, mice and birds. It’s a super shy and non-aggressive species - if it comes across anything it can’t swallow, it'll be out of there so fast, the thing it couldn't swallow probably won't have even noticed it was there. It's also basically the cat of the snake world, often moving into the enclosed nests of nearby birds so it can curl up and hibernate in peace during the winter months. Quit whinging birds, you got flight, you can’t complain about anything ever.
On top of their non-aggressive tendencies, the way boomslangs are built means you have to be extremely, extremely unlucky to be bitten by one. Known as ‘rear-fanged’ snakes, their fangs are positioned way back in their mouths behind several other teeth, which means to inject someone with venom, they have to open their mouths really wide - up to 170 degrees - so they can wrap them around the flesh and stab. There have so far been less than 10 recorded deaths from boomslang bites around the world.
Because they’re so anatomically unsuited to biting people, boomslangs were assumed to be harmless up until the late 1950s. A fantastic article by Paul Donovan for Reptiles Magazine describes how on the 26th of September 1957, eminent herpetologist, Karl P. Schmidt from Chicago's Lincoln Park Zoo, died from a boomslang bite. It was the first such recorded death, and it left his peers shocked. Schmidt had received a bite from a single fang in his thumb as he opened a sack containing a young boomslang that had spent its life in captivity, and he thought nothing of it. Not only did the scientific community think this species posed no threat - very few rear-fanged snakes in the family Colubridae are dangerous to humans - but the way its venom works means that the symptoms don’t kick in until several hours after the bite. Schmidt recorded every symptom as it arrived. Around 24 hours after his bite, Schmidt was found dead in his home from respiratory arrest and severe brain haemorrhaging.
"The [Chicago] Tribune said the diary covered a 15-hour period from the time he boarded a suburban train on the day he was bitten until the next morning. Associates said he believed he had recovered and was planning to return to work. The last entry was made after breakfast Sept 26. Associates said Dr Schmidt apparently made no further entries because he was up and around later in the morning and had notified the museum he would be back at work the next day. Unattended by a physician, he went into a coma at 2pm."
Donovan, himself a renowned snake expert, describes the impact of Schmidt's death on the herpetological community, saying, "Schmidt's death changed our perception of the boomslang, and subsequent analysis of its venom found it to be as toxic, if not more toxic, than many front-fanged snakes. Today, the boomslang ranks as one of Africa's most venomous snakes.”
While the venom causes several symptoms such as headache, nausea, and sleepiness, the real worry is its anti-coagulating properties. The venom is a hemotoxin, which means it destroys red blood cells, loosens blood clotting, and causes organ and tissue degeneration. Victims suffer extensive muscle and brain haemorrhaging, and on top of that, blood will start seeping out of every possible exit, including the gums and nostrils, and even the tiniest of cuts. Blood will also start passing through the body via the victim's stools, urine, saliva, and vomit until they die. "Death is attributed to progressive internal bleeding, and it can be a slow and lingering process, taking anywhere from three to five days,” says Donovan at Reptiles Magazine. "Interestingly, many bite victims report "seeing with a yellow tinge," which may be due to bleeding inside the eyes.”
The fact that the venom is relatively slow to act in humans means that bite victims have some time to get access to the anti-venom and be saved, but it also puts those who don't know any better at serious risk. During those few crucial hours of grace, they assume there’s nothing to fear.