Whales are some of the largest living animals. They live in the ocean, having fully adapted to living in the water. They are mammals!

Sharks are known for being apex predators, but some sharks only eat small fish. Sharks teeth never stop growing, with old ones constantly falling out and being replaced by new teeth.

Dolphins are highly intelligent animals, demonstrated by their curiosity and complex social structure. Although they live in the ocean, they breathe air. Lucky for them, they can hold their breath for up to 15 minutes.

Octopuses are also very intelligent animals. There are several cases of octopuses escaping from aquariums. They are able to change the color and even the texture of their skin at will!