hippopotamus, hippo, river horse, Hippopotamus amphibius
['axolotl, mud puppy, Ambystoma mexicanum', 'diamondback, diamondback rattlesnake, Crotalus adamanteus', 'sea snake', 'dock, dockage, docking facility', 'black swan, Cygnus atratus', 'limpkin, Aramus pictus', 'Irish water spaniel']