Like all other spiders, tarantulas have eight legs. The largest variety of tarantula, the goliath birdeater, can have a leg span of nearly 12 inches across at full-grown size.
The term "tarantula" applies to many varieties of large spiders. According to National Geographic, there are hundreds of tarantula species around the world, but what typifies them is their relatively generous size and a dense coating of stinging hairs on their abdomens and legs. These spiders are also able to regrow lost legs throughout their lives during periodic molting phases in which they shed their exoskeletons. All tarantulas have two claws and a softer footpad at the end of each leg; these features enable them to climb efficiently on smooth surfaces and retract for ease of movement across rougher terrain.