Sydney Funnel-web Spider
Spiders who weave funnel webs are found in many parts of the world, but the scariest one of them all is the Sydney funnel-web spider, Atrax robustus, which lives within 100 miles (160 kilometers) of Sydney, Australia. These creatures have a body that's about 1.4 inches (35 millimeters) in length.
But the spider, which looks a bit like a tiny black leather glove formed into a fist, possesses a fearsomeness that isn't all show. These spiders are extremely aggressive and venomous, and the males have very strong fangs. A bite from this spider can be fatal if not treated immediately, so watch out [source: Fathallah].