Overqwil is a large, spherical Pokémon that resides in the sea. All over its body are overgrown conical spikes whose colors correspond to those on Overqwil's body. Its top half is a black color while its bottom half is light yellow. In the middle of its body, the two colors create a pattern. The spikes on the top half of its body have parts of purple at their tips and there are two very long spikes at the top and bottom of its body that jut out in a straight direction. Above its eyes and around part of the top half of its body, Overqwil has circular purple dots. Its lips also have a purple coloration and appear puffy, and its small light yellow eyes have purple pupils and are always fixated in an annoyed expression. In between its eyes are two pairs of spikes, the outer ones being longer and resembling eyebrows. Its large tail appears flat with a black outline and a purple inside, which also has a pattern that resembles the letter "Q."
Overqwil has a very aggressive personality along with a short temper, which has given it the nickname "sea fiend." Its diet consists of poison. Overqwil's poisonous spikes will react automatically even while Overqwil sleeps. The barbed spikes will stab any moving thing that approaches Overqwil. Once the barbed spikes have punctured a target, they cannot be removed so easily. It has been recently seen along with its pre-evolution, offshore in cold parts of the world.
