 It is not technically a tarantula, but it is fairly large (4- to 5-inch legspan), somewhat ″hairy″, and is highly venomous to humans.Another dangerous type of spiders that have been confused with tarantulas are the Australian funnel-web spiders.The best known species of these is the Sydney funnel-web spider ("Atrax robustus") a spider that is aggressive, highly venomous, and (prior to the development of antivenom in the 1980s) was responsible for numerous deaths in Australia.