1849 25 The River Jack. Clotho nasicornis... River Jack, Colonists.
1877 Oct. 531/2 A River Jack Viper (Vipera rhinoceros) from West Africa.
1955 G. Cansdale iii. 49 The Rhinoceros Viper..is found frequently in the actual river valleys and swamps; because of this it is often called the River Jack.
2003 (Nexis) 5 Aug. The rhinoceros viper, also known as the river jack, is a 28-inch long, 3-pound male.