Penguins Enemies, Bro

Although docile in nature, even Emperor penguins have predators, the Leopard seal, the Southern Giant petrel, the Skua, the Orca and sharks

Emperor penguins predators – The Leopard seals
The Leopard seal likes to chow down on penguins and uses his incredible sense of smell and incredible underwater eyesight.
Much like the penguin, the leopard seals body is shaped to skim through the water like a graceful killing machine. The front teeth of the Leopard seal are sharp and deadly to penguins but the molars allow them to sieve krill. The Leopard seal is not satisfied with just the one type of penguin, they also like a bit of King penguin! The only thing that could stop a leopard seal is an Orca, who is coincidentally another Penguin hunter.
Even though the leopard seal is bigger, faster, stronger, more aware of his surroundings AND designed to kill, he still chooses to be sneaky when hunting penguins! He waits in the water by the ice edge, waiting for the penguins to dive in, then he grabs the penguin by its feet and murders it by smacking it against the surface of the water until dead. This will also skin the penguin, making it more edible.

The Southern giant petrel
The Petrel is a massive seabird.

How big you say? The two species that are biggest members of the petrel family can have a wingspan up to 190 centimetres (6.2 feet).
It is incredibly aggressive; it feeds on land and sea and has been known to scavenge.
They are particularly known to scoop up young penguins that have wandered too far from the colony.
Fortunately penguins are usually in a large group and Petrels usually work alone. Unless a petrel is starving it would rarely attack.