The helmeted hornbill (Rhinoplax vigil) is a very large bird in the hornbill family. It is found on the Malay peninsula, Sumatra and Borneo. The casque accounts for some 11% of its 3 kg weight. Unlike any other hornbill, the casque is almost solid, and is used in head-to-head combat among males. It is a belief among the Punan Bah that a large helmeted hornbill guards the river between life and death.