Matadogas

Weezing is a purple Pokémon consisting of two spherical heads connected by a thin tube with another sphere in the center. The heads have different sizes and features. The left head is larger and has prominent eyebrows, pointed teeth protruding from its lower jaw, and two flat teeth in its upper jaw. The smaller, right head simply has two pointed teeth, one at each corner of its mouth. The larger head has a cream-colored skull-and-crossbones marking below its face, while the smaller head has a ring marking instead. It is covered with many geyser-like protrusions, which usually expel mustard-colored gases. Weezing is said to form when poisonous gases pool and two Koffing fuse over many years. Very rarely, two Koffing can become a Weezing in a short time span because of a sudden mutation. Triplet Weezing have been discovered, although they are extremely rare.

Each of Weezing's heads contains a different toxin. It mixes its gases by inflating one head and deflating the other. When its gases mix, Weezing becomes more toxic and putrid. Weezing can hover in midair, presumably due to gases lighter than air, as is the case for Koffing. Despite their stench and poison, Weezing's gases can be used to make top-grade perfume by diluting them to the highest level.

Weezing lives in urban areas. It seeks a dirty, unkempt house and nests there. At night, when the people in the house are asleep, it will go through the trash. Weezing feeds on the dust, microorganisms, and especially gases emitted by garbage and toxic waste. Weezing's body expands and smells worse upon inhaling poisonous gases. The Kantonian Weezing used to be common in Galar and created more potent toxins than their Galarian relatives.

Forms
Weezing has a regional form: Galarian Weezing.

In the Galar region, its appearance has changed due to absorbing polluted air from factories. It has a gray body with the skull, crossbones, and ring patterns changed to the color yellow. Both heads have a hat-like tube located on top of them that constantly releases purified air. Five puffs of green poison gas clouds can be seen floating around it. The gas clouds also partly cover its faces: the larger head has a mustache-like cloud on its upper lip, while the smaller head has clouds on its face in the shape of eyebrows and a beard.

Galarian Weezing consumes particles from polluted air and expels clean air instead of droppings. The toxins within Galarian Weezing's body are accumulated into poison gas clouds that leak and drift around it. The gas is its best weapon in battle, being potent enough to stun and immobilize an opponent with just a whiff. Galarian Weezing preys on for the fumes it produces.

Evolution
Weezing evolves from .
In Galar, Weezing has a regional form that evolves from Koffing.

(Source: Bulbapedia)