Prinplup is a blue, penguin-like Pokémon. It is mostly dark blue with light blue facial markings, wing tips, and lower body. Its eyes are blue and it has a short yellow beak with a small point above it. Two large, yellow ridges extend from its beak over the back of its head and meet just above the nape of its neck. On its body are four large, white spots that resemble buttons. Instead of arms, it has long, sturdy, flipper-like wings that are capable of knocking over and snapping trees. It has short legs with yellow, three-toed feet.
Prinplup has a high sense of self-pride, which prevents it from forming groups of its own kind. This Pokémon can be found in icy waters, where it hunts for prey. Prinplup can swim gracefully in the cold seas. Its singing voice has been compared to a roaring tide.
Prinplup shares its category with its pre-evolved form and Eiscue. They are all known as the Penguin Pokémon.
Prinplup is based on a penguin. The crests on its head suggest it may be based on a species of crested penguin. Prinplup's body looks like it is clothed in a tailcoat adorned with buttons, often likened to the black and white plumage of penguins.
Prinplup may be a combination of prince and plup (sound of a pebble hitting water).
Pottaishi may be a combination of ぽちゃぽちゃ pochapocha (sound of a pebble splashing in water) and 皇太子 kōtaishi (crown prince).