Atrax

Atrax is a genus of spiders. They have very strong venom. These spiders aggressively defend their territory and chase off attackers who may scare them by making a threat display. Next they will bite. The fastest death occurred in 1927 when a young boy died within fifteen minutes of being bitten. Thirteen deaths were recorded in the fifty years before antivenom was invented for this spider's bite. In English they are sometimes called Sydney Funnel Web spiders because they come from around that part of Australia.
Under the heading "spiders" (Aranae) there are three main groups. One is so very old that only a few species still live on earth. Another is the group that includes the spiders that can be seen making webs or chasing prey almost everywhere in the world. The third group includes the tarantulas and a few other kinds of spiders. The Atrax spiders belong to this third group.
There are also species called "funnel-web spiders" that belong to the second group mentioned above. So they are not close relatives of Atrax, and they are not dangerous. They just have a similar way of making a funnel-shaped web that leads down to some kind of shelter where the spider hides in wait for some insect to eat. Atrax is a very large and very aggressive spider, and these other spiders are from small to medium size and are extremely timid.