Why do killers whales are the enemy of a penguin?

Killer whales (also called orcas) are predators to most of the animal life in the oceans, including penguins.

Killer whales are very intelligent mammals and are apex predators, which means that they have no natural predators. They are found in all the world's oceans and are known to hunt and eat at least several types of penguins, including Adélie, Chinstrap, Emperor, Gentoo and Magellanic penguins. To eat the penguins, they use different hunting strategies, depending on the circumstances, like working together to create waves that can wash penguins into the ocean or beaching themselves on shore to catch penguins as they flee into the water.