Answer:

Penguins are mostly monogamous. However, there are some species like the Emperor Penguin which is serially monogamous; they mate with one couple for a season, but the next year they will probably mate with another penguin as the urgent need for breeding will make them avoid waiting for the same couple of the previous year.

African, Magellanic, Gentoo and Royal penguins are examples of monogamous penguin species. A fascinating fact regarding the mating of penguins is that both, male and female, are involved in the preparation of the nest and the care of the chicks, a behavior hardly seen in many species of animals.