A yarara, scientifically named Bothrops jararaca, is a medium-sized venomous species of pit viper. A mature yarara is fairly slender and measures about 32-63 inches (80-160 cm) in length, with the female usually somewhat longer than the male. In appearance, individual snakes of this species can differ significantly from each other because of the variety of skin tones that these snakes can have. Skin colors come in shades of olive, maroon, yellow, tan, brown or gray. Yararas do share certain physical characteristics, such as dark blotches that come in a variety of shapes and sizes on their backs and pronounced dark-brown stripes on the head that run in an angle from the mouth to just behind the eyes.