According to Guinness World Records the Brazilian wandering spider is officially the world’s most venomous spider. It is capable of injecting a powerful neurotoxin which is nearly 20 times more deadly that that of the Black Widow spider if it gets into the blood stream. That is as potent as the venom of many deadly snake species and the effects are similar. The symptoms of envenomation include a loss of muscle control leading to breathing problems which can result in complete respiratory paralysis and eventually asphyxiation.