Mastigoproctus is a genus of whip scorpions. Native to the rain forest regions of northern South America, these whip scorpions can reach a length of up to 9 centimetres (3.5 in) and can weigh over 30 grams (1.1 oz). Despite popular belief, they are not venomous as, like all other whip scorpions, they do not possess venom glands.