Goliath Birdeater Theraphosa blondi

Despite its fearsome name, this tarantula is the largest spider in the world by mass and body length — a crown it wears impressively at up to 12 inches across. But here's the surprise: despite being called the "bird-eating spider," it rarely actually eats birds. The name comes from an early 18th-century engraving by Maria Sibylla Merian showing one eating a hummingbird, an image so striking that it stuck forever.

Found in the rainforests of northern South America, this Goliath prefers much smaller prey and relies more on its massive size and intimidating fangs as deterrents than as tools for hunting birds. It's considerably larger than any known prehistoric spider, making it a true giant among arachnids.