Eudyptula is a “monotypic” genus. It comprises only a single species, the Little Penguin. The Little Penguin is different in many ways from all other penguins. It is the smallest of all penguins and the only nocturnal species. Its more horizontal posture gives it a different silhouette compared to the upright stance of other species.

In many respects, however, Eudyptula is an Antipodean version of Spheniscus, the genus of banded penguins. Just as with Spheniscus, Eudyptula breeds in burrows and generally forages close inshore. Even more striking is the close resemblance of juvenile Spheniscus with Little Penguins.