After the elephant and rhinoceros, the hippopotamus is the third-largest type of land mammal and is the heaviest extant artiodactyl


Crocodiles (family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia.

sea otter

Otters are part of the mammal family called mustelids, which includes ferrets, badgers, minks and weasels.

water snail

At least 33–38 independent lineages of gastropods have successfully colonized freshwater environments.


They are unique in appearance, with their horselike head, prehensile tail, independently moving eyes, and brood pouch.


They are about 71 – 76 cm tall and weigh about 4.5 kg and are the most numerous of penguins, with a population of about 12-13 million,


Octopuses appear in mythology as sea monsters like the kraken of Norway and the akkorokamui of the ainu, and probably the gorgon of ancient Greece.

sea snakes

All sea snakes have paddle-like tails and many have laterally compressed bodies that give them an eel-like appearance.


These animals build their holes at the very edge of the water and feed on underwater worms, mollusks and insects.