Swinub is a small porcine Pokémon. Living in frigid temperatures, Swinub is covered in dense, brown, striped hair to keep it warm. The hair is so shaggy that it often covers its tuft-like small legs, making it appear like a legless lump. Swinub's eyes appear as if they are perpetually closed.

Swinub uses its pink, pig-like nose to dig through mud and snow, looking for anything edible. In Hisui, ancient people relied on Swinub a lot because of this skill. Occasionally, it will come across hot springs while scouring the ground. Its favorite food is a type of mushroom that grows beneath dead grass, though it also eats Berries. When a Swinub finds an attractive smell, it will run desperately to find out the source of the aroma. It inhabits cold places, such as icy caves, mountainous regions, and frozen tundra.