Ducklett is light-blue, duckling-like Pokémon. It has two feathery tufts on its head that connect at the bottom, forming a V-shape. It has a darker blue, feathery underside which makes it appear as if it were in mid-moult. It has yellow, webbed feet and a small tail. Ducklett lives around ponds and rivers. It is a talented diver and can spray water from its feathers for self-defense. The foe is distracted by the spray, allowing Ducklett to escape.
In The Pirates of Decolore!, a Ducklett was the fourth member of Croconaw's gang. It was responsible for keeping the raft they traveled on from drifting away. Ducklett later joined Officer Jenny's squad after participating in the Darumaka rescue.
Ducklett shares its category with Pelipper. They are both known as the Water Bird Pokémon.
Ducklett seems to be based on a duckling or cygnet. Its bottom plumage also resembles a swim ring, while its evolved form has similar plumage that resembles a bikini. Its name suggests that its evolutionary line may also be based on the fairy-tale The Ugly Duckling, in which the "ugly duckling" someday becomes a beautiful swan.
Ducklett may be a corruption of ducklet, possibly combined with wet or -ette (suffix meaning small).
Koaruhie may be a combination of 子 ko (child) or 小 ko (small) and a corruption of 家鴨 ahiru (duck).