Emperor Penguins!

These penguins are the biggest and baddest of all the penguins, weighing in at an average 22-45kgs with an average height of 122cm!
Their body's are, like most penguins, designed to be incredible swimmers, slipping through the water with ease ;)
They can stay under the water for up to 18 minutes and can function at low oxygen levels and they can slow down their metabolism as well in underwater emergencies! Their bones are solid as well, to stop barotrauma
Penguins are pretty much designed to swim!
Perhaps what these bad boys are best know for is their mating process. During the antarctic winter there is no sun, making it ridiculously cold, so the girl penguins leave the eggs with the boys, the girl goes to get food and the males all huddle together with the egg between their legs, keeping it warm.
Their lifespan is 20 years in the wild but up to 50 in captivity!