I haven’t seen Emperor Penguins in the wild, as their breeding spots on the ice are far away from tourist access, and that’s fine. But they do have a long march to the sea when they’re growing up. In this video clip from BBC Earth, a group of juvenile Emperors is having their March to the Sea when they’re attacked by a giant petrel. He doesn’t succeed in hurting them, though, and for several reasons. First, they form a defensive circle facing outwards, and one of the chicks takes a protective stance with its wings out. (I find this amazing, but surely it’s hard-wired into the juvenile nervous system.)
And then an aggressive Adelie penguin shows up, further protecting the Emperors. Adelies are very small but they don’t take guff. What I don’t get in the video is that the fluffy chicks, who haven’t yet molted into adult plumage, are said to be ready to swim. They’re not. They won’t start swimming and fishing until they get their adult plumage.