An extreme amount of people have died all over Africa due to bites from a Black Mamba. These snakes are able to strike up to 12 times in succession and each bite is loaded with colossal amounts of neurotoxin. Scarily enough, a Black Mamba bite can pump enough venom into you with just a single bite, killing you up to 25 times over. If untreated, a bite is almost 100 percent deadly, quite often death occurs in as little as 15 minutes.
Black-banded sea krait
The black-banded sea krait can be found in most of the warm waters of the western Pacific Ocean. Their venom is also ten times stronger than a cobra which means, bingo, they are very, very dangerous. Moreover these snakes tend to shy away from humans and will only attack if provoked.