The Boomslang is a pretty little snake that likes to hang out in trees in sub-Saharan Africa. It's usually pretty shy and doesn't attack all that many humans, which is a good thing as, when it does, it's completely horrific. Boomslang venom is what is known as a haemotoxin, which means that it destroys blood cells, cause organ damage and, most importantly, prevent clotting. The upshot of this is that the recipient of a Boomslang bite will bleed uncontrollably inside and out, including into their brain and out of every orifice in their body. Yep, that includes nose, eyes, ears, urethra, anus and any other hole you happen to have. To add insult to (horrendous) injury, the venom is slow-acting and symptoms will not become apparent until long after you have been bitten. On the plus side, this gives you plenty of time to go get the anti-venom. On the downside, this means that people may think that they're perfectly fine, as it is common for a snake to fail to release venom (known as a dry bite). This means that the first clue you get to the fact that you're dying is when you start crying blood. Fun Fact: In 1957, the herpetologist (that's someone who studies reptiles and amphibians) Karl Schmidt was bitten by a juvenile Boomslang that he was supposed to be identifying. Schmidt (wrongly) believed that a bite from the youngster would not kill him and so did not seek help. When it became apparent that he was dying, he began recording his symptoms and refused any medical intervention because it would ruin his scientific observations.