Emperor penguins are the biggest of all penguins.
Emperors are so big they have to mate at the beginning of winter as there is not enough time in the short Antarctic summer for the chicks to grow into sea-going adults.
The females then return to the sea, leaving the eggs with the males who hold them on top of their feet to keep them off the ice.
The male Emperors cannot feed for four months. All they can do while waiting for the females to return is endure the most demanding of conditions on earth and maybe watch the southern lights. Then the females will return allowing the males to venture to the sea for a feed.