Great Spiders are a fictional sapient species featured in J.R.R. Tolkien's Works.
Great Spiders are the offrsping of the spider-like goddess Ungoliant and various lesser, non-sapient spiders. The Great Spiders soon replaced their animalistic elders in the ecosystem of Middle-Earth. They were able to talk, though they were quite uncilivized, and their size could range anywhere from the size of a dog to that of an elephant. The largest and most dangerous Great Spiders were the direct offspring of Ungoliant, such as the female Great Spider Shelob; these were cleverer than their descendance and some at least were apparently immortal.