• Large or Great Penguins The two largest penguin species, the king penguin and emperor penguin, are so much larger than other penguin species that they are a distinct group of their own.
• Brush-Tailed Penguins These mid-sized penguins have distinct bristled, bushy tails that are longer than most penguin's tails and are useful as rudders when swimming or tobogganing.
• Crested Penguins The aptly-named crested penguins all have some type of bushy eyebrow crests that show how closely they are related. The length, density, and coloration of the crests vary between the different crested penguin species.