What is the largest species of penguin, measured by height and mass?

The emperor penguin is the largest living penguin species by height and mass.

Adult emperor penguins can stand about 100–130 centimetres tall, and their mass varies substantially through the breeding cycle. They lose weight while fasting during the Antarctic breeding season, then regain it while feeding at sea. Their large bodies reduce heat loss relative to smaller penguins, an advantage in extreme cold.

Emperor penguins breed during the Antarctic winter. After the female lays a single egg, the male balances it on his feet and covers it with a warm fold of abdominal skin. He may fast for roughly two months while incubating, although timing varies with conditions and colony movements.

The species is adapted for deep diving and cold-water life. It has dense feathers, a thick fat layer, and countercurrent heat exchange in its limbs. The king penguin is the second-largest living penguin, but it breeds in milder subantarctic environments.