The Brazilian itinerant Spider (Phoneutria) or banana spider appears in the Guinness Book of World Records 2007 for the majority venomous spider and is the spider accountable for most being deaths.
This spider is supposed to have the most potent neurotoxin venom of any living spider. Only 0.006mg (0.00000021oz) is enough to kill a mouse. They are also so dangerous because of their wandering nature. They frequently hide during daytime in highly populated areas inside houses, clothes, boots, and cars.
Its poisonous bite cause not only intense pain, the venom of the spider can also cause priapism – painful erections lasting for many hours that guide to impotence.