5. Death Stalker Scorpion Contrarily to the popular belief most of the scorpions are relatively harmless to humans as stings produce only local effects (pain, numbness or swelling). However, the Death Starker Scorpion is highly dangerous species because its venom is a powerful cocktail of neurotoxins which causes an intense and unbearable pain, then fever, followed by coma, convulsions, paralysis and death. Fortunately, while a sting from this scorpion is extremely painful, it would be unlikely to kill a healthy, adult human. Young children, the old, or infirm (with a heart condition) are at the biggest risk.
6. Stonefish
Stonefish venom causes such a severe pain that the victims of its sting want the affected limb to be amputated. It is described as the worst pain known to man. It is accompanied with possible shock, paralysis, and tissue death. If not given medical attention within a couple of hours it can be fatal to humans.
7. The Brazilian wandering spider The Brazilian Wandering Spider (Phoneutria) or banana spider appears in the Guinness Book of World Records 2007 for the most venomous spider and is the spider responsible for most human deaths.
This spider is believed to have the most potent neurotoxic venom of any living spider. Only 0.006mg (0.00000021oz) is sufficient to kill a mouse. They are also so dangerous because of their wandering nature. They often hide during daytime in highly populated areas inside houses, clothes, boots, and cars.