The "Araña de Rincon", which could be translated as "Corner Spider" or "Cranny Spider", biological name Loxosceles laeta, is a spider native to Chile and some of the surrounding countries. It is related to the Brown Recluse, and is sometimes called "The Chilean Recluse" spider. Its appearance, habits and venom are all similar to other Loxosceles spiders, being a medium sized, light brown spider with a small body. As its name suggests, it lives in dark and isolated places (thus its name), and hunts at night, and will withdraw immediately from light or motion. Its venom is similar to those of other Loxosceles spiders, causing local swelling and sometimes necrosis of tissue, as well as systemic reaction and sometimes death. It is considered to have the most dangerous venom of the Loxosceles spiders, being several times more dangerous than the Brown Recluse of North America.
The first image many people from North America and Europe might have of South America is of a place teeming with animal life, much of it buggy and crawly and poisonous. And while that might be true of much of the continent, Chile is an exception. The dry, and often cool, climate limits insects and spiders, and the barriers of the Andes Mountains and Atacama Desert, limit the fauna of Chile. Chile is the only country in the mainland of the Americas with no venomous (to humans) snakes, for example. The poisonous spiders of Chile consist of a field-dwelling relative to the Black Widow that rarely comes into human contact, and the Araña de Rincon, which lives in buildings, and often does come into contact with people. I think that due to being one of Chile's only dangerous animals, the Araña de Rincon gets more attention than perhaps it is due.
Not that it isn't dangerous. It is. If you are curious and have a strong stomach, do a google image search, but don't blame me when you see the results. A bad case can involve tissue rotting away, leaving a permanent scar. I have seen "mild cases" in person, and even a mild case, treated with steroids and antibiotics, was a swollen, four inch wide blue bruise across the thigh. But there are two things to remember about the Araña de Rincon: it is not aggressive, and a person has to contact it to be bitten. Most bites happen when a person puts on a piece of clothing with a hiding spider. I have read that even then, many bites go unnoticed. Only in some cases does the bite show serious symptoms. I have also heard many people here claim that spiders are Arañas de Rincon that don't match the description: for example, the fast-moving, light-hating Araña is not likely to sit on a wall in the middle of the day, but I have heard some people here to claim any spider is an Araña de Rincon.
Like many things, while the Araña de Rincon can be dangerous, its overall habits mean that it is relatively easy to avoid. And even though the bite can be fatal, lethal bites are rare, a study of bites in 2005 showed no fatalities. As with many other things, the danger of the Araña de Rincon seems to be exaggerated out of some sort of perverse pride in its danger.
Information, in Spanish, about the Araña de Rincon: