The Speckled Rattlesnake, or Mitchell’s Rattlesnake, is a venomous pit viper in the western US and Mexico. It blends in with the rocky terrain thanks to its speckled skin. 

It is active at night, feeds on small mammals, birds, and lizards, and gives birth to live young. 

When threatened, this type of rattlesnake rattles its tail and strikes with potent venom. A recent study reports its venom constitutes crotoxin and serine proteases2, which can lead to muscle weakness, vision problems, and uncontrolled bleeding.