underwater
africa
african
alone
animal
animals
artiodactyla
even toed
even toed ungulates
fauna
hippo
hippopotamidae
hippopotamus
hippopotamus amphibius
hippopotamuses
hippos
hoofed animals
lake
mammal
mammalia
mammals
natural
nature
one
one animal
only
river
species
sunken
surface
under
ungulate
water
wild life
wildlife
zoo