If you shriek in fear at the sight of the tiniest of spiders, you may want to avoid the rainforests of Suriname, Guyana, northern Brazil and southern Venezuela, where the Goliath birdeater dwells! Listed in the Guinness World Records as the world's biggest spider, the terrifying-looking arachnid weighs a hefty six ounces, (almost the same weight as a newborn puppy), and has a leg span that extends out 11-inches (the size of a child's forearm).