The Goliath birdeater (Theraphosa blondi) is a spider belonging to the tarantula family Theraphosidae. Found in northern South America, it is the largest spider in the world. By leg-span, it is second to the giant huntsman spider, but it is the largest by mass.[1] It is also called the Goliath bird-eating spider; the practice of calling theraphosids "bird-eating" derives from an early 18th-century copper engraving by Maria Sibylla Merian that shows one eating a hummingbird. It only rarely preys on adult birds.[2]