Tailed forest spider
Arachnura is a genus of orb-weaving spiders of Australasia, with one species found in Africa and Madagascar. These spiders mimic litter, like twigs or dead leaves, by a brownish color and appendages. They stay at the middle of their web day and night. Among the common names are Tailed spider, Scorpion-tailed spider and Scorpion spider. They do curl up their tail when disturbed, but this tail is completely harmless, as they are not closely related to order scorpiones. Bites are rare, and result in minor symptoms such as local pain and swelling.
Females are between 1 and 3 cm long, males reach only 2 mm and are tailless.
A. logio is called Kijiro o-hiki-gumo in Japanese. A. feredayi is commonly called Tailed forest spider. A. higginsi is often found in large numbers near water in Australia. source