The American Rattlesnake is a species of venomous pit viper found in North America. It is also known as the Massasauga, which is derived from an Ojibwe word meaning 'great river-mouth'. The Massasauga is a medium-sized rattlesnake, typically growing to between 20 and 30 inches in length. It has a distinctive rattle at the end of its tail, which it uses to warn potential predators. It is a shy and reclusive snake, preferring to avoid contact with humans.