Mr. Vile posted:

Venomous snakes in general are far more dangerous to humans than any spider or scorpion, both because they're larger and thus have far more venom to inject, and because they generally eat small mammals and so have venom that is effective against mammalian biology, rather than having evolved to discrupt invertebrate systems. The most dangerous spider in the world (to humans) is generally considered to be either the Sydney funnelweb (Atrax robustus) or Brazilian wandering spider (Phoneutria). There have been no fatalities from funnelweb bites since 1981 when the antivenom was devoloped, and only around 2% of wandering spider bites are serious enough to need antivenom in the first place. Which is not to say that they're incapable of killing a human, just that even the deadliest of them are not nearly as dangerous as, say, a sociopathic rear end in a top hat with a shovel.