Ahaetulla nasuta. When startled they are capable of changing their color from bright green to a checkered black and white warning pattern. In duress they also gape open wicked smiles to threaten off potential predators. The snakes are viviparous and have astonished zookeepers by giving birth after being alone for years. Herpetological dispute as to whether the female snake is able to delay fertilization within her body for extremely long periods of time or is capable of parthenogenesis.