What does penguins eat

Enemies

In the water

Leopard seal are the most dangerous enemies of the penguins. They wait underwater near the coast and snap immediately when a penguin passes them. Also Whales sometimes penguins eat when a penguin accidentally lands in it when they open their huge mouth.

On land

Skuas (also called skuas) look for eggs from certain species of penguins during the breeding season. If a penguin strays too far from its nest or is careless, they snap to it immediately.
Even the newly hatched chicks are only safe from skuas if they are protected by their parents or other adult animals. But thanks to their skillful hunting techniques, the Skuas occasionally manage to push chicks out of the kindergarten, which then serve as easy prey.

Giant petrels From the air pounce on sick and weak chicks, but also on dead adult animals. In addition, they can also be dangerous in the water: emerging penguins or the as yet inexperienced young animals are not safe from other birds even in the water.

The human used to be an enemy of the penguins as well. David Salomon writes in his book "Penguin-Pedia" that the seafarers used penguins and their eggs as food on their voyages. In addition, the fat was an alternative fuel source for smaller ships. Since the penguin oil was not suitable enough, marine mammals were killed instead. A law was later passed prohibiting the killing of penguins and seals.
In places like Simonstown in South Africa, where the habitats of penguins and humans intersect, the Pets humans are also a danger. Cats and dogs often plunder or destroy the nests.

Swell:

What is What Volume 107 "Penguins" by Boris Culik
Penguin Pedia by David Salomon (English)