Giant huntsman spider (Heteropoda maxima)
The Goliath birdeater may be the world’s largest spider by mass, but the giant huntsman spider is the world's largest when measured by leg-span: an adult male’s leg-span can measure up to a staggering 10-12 inches long. This eight-eyed cave-dweller lives (thankfully) far, far away in Laos, but other fast-moving members of the family Sparassidae, which sport crab-like walking appendages, live in numerous parts of the world. And for those of you who voted for the daddy longlegs, we've got news for you: the insect commonly ID’d as a daddy longlegs is not, in fact, a spider at all but an order of distant arthropod relatives known as harvestmen (Opiliones). However, to further confuse things, cellar spiders (pholcus phalangioides) are also frequently referred to as daddy longlegs as well.