The napoleon wrasse (Cheilinus undulatus), also known as the Humphead or Maori Wrasse, is one of the top predators of healthy tropical coral reef systems in the Into-Pacific region. It is a protogynous hermaphrodite species with the female transforming into a male at about 9 years old. Males can reach 2 meters and females rarely more than a meter in length. The males are characterised with a large hump on their forehead.