White Tailed Spider
Family: Lamponidae (White-Tailed Spiders, 200 described species in 23 genera, mostly endemic to Australia)
Size: Body up to 18 mm, leg span up to 28 mm.
Distribution: White-tailed spiders are spiders native to southern and eastern Australia.
Danger: I'm pretty sure I was bitten by a while-tailed spider once. I found one in my bed, and at that time I had a large welt on my leg, kind of like a mosquito bite but about 1 inch (2.5 centimetres) across, and much more itchy than a mosquito bite. I forget exactly how long it stayed there, I think about 1-2 weeks. I was living in the Northern Beaches area of Sydney at the time.
Many sources state that the urban myth of white-tailed spiders rotting flesh is just a myth and has never been substantiated. A video at the Australian Museum talked about several cases where roting flesh and other very nasty symptoms that were originally blamed on white-tailed spiders were later found to be something else entirely, likea golden staph infection for example.
Note that dead spiders usually fade in colour, so nearly all the spiders will look blacker or darker in colour in real life than they do in the photos of dead spiders from the museum.
Photo taken at Australian Museum, Sydney. High Resolution 3232 x 2040.