
Black mamba : These species is the fastest of all snakes . Thankfully , black mambas usually only strike when threatened - but when they do , they will bite repeatedly , delivering enough venom in a single bite to kill ten people .

Tsetse fly : Often regarded as the world's most dangerous fly as its true terror lies in the protozoan parasites they spread known as Trypanosomes .

Puffer fish : Also known as blowfish , they are the second most poisonous vertebrate on the planet . They are arguably more dangerous as their neurotoxin is found in the fish's skin , muscle tissue ,liver ,kidney and gonads , all of which must be avoided when preparing the creature for human consumption .

Indian saw scaled viper: These reptiles live in some of the most populated regions , which stretches well beyond India . Even with a warning , saw scaled vipers are extremely aggressive , with more than double a lethal dose into each bite .

Cone snail : Instantly recognisable for their highly prized brown - and - white marbled shells. Their concealed harpoon -like teeth contain a complex venom known as conotoxin, making them one of the most venomous species of snails.