Fiddleback spider, often called the Mediterranean recluse, is a venomous spider native to the Mediterranean region. The spider is about 7/16 inch (1 centimeter) long, lightly built, and has slender legs. It is brownish in color, often with a darker fiddle-shaped mark extending back from the front. The fiddleback is among the most venomous spiders. It has spread to many parts of the world, including Australia and North America.