Anitpodeans are always hard to classify. A Guillemot (flying Penguin) is not far off a Pigeon (INXJ) and in roughly the same category as Chickens and the smaller Tell Tale Tits. But Chickens are not cowards, although they can be the Wicked Messenger.
Do you think if penguins had the choice, they would choose to be able to fly rather than to be able to sledge?
According to Terry Pratchett (Guards! Guards!) the Watch can have an underdeveloped Dragon (PN) as a Mascot (Errol). But the Dragons cannot be harshly punished (or treated like a Hamster ISFJ), and not even Dogs (ISTJ) especially Lion-chasers can be brutalised.