Weezing

Weezing is a Poison-type Pokémon and the evolved form of Koffing. When two Koffing spend a long period of time mingling in their shared gases, they fuse together into a shared body. One "head" is larger than the other and has large fangs jutting up from its lower lip. The smaller head has tiny fangs protruding from its lower lip and a circular marking where there was once a skull-and-crossbones. A vestigal third orb, Weezing's "tail", is connected to both heads by a pair of tubes.

Pokédex Data
Each of Weezing's heads contains a different type of gas. It mixes these gases by deflating one head and inflating the other. When these gases mix, Weezing's expulsions become even more noxious than before. Despite their stench and poison, Weezing's gases can be used to make top-grade perfume by diluting them to the highest level.

Weezing inhabits urban areas, finding the filthiest alleys or abandoned buildings to make their nests. They feed on dust, garbage and especially have a fondness for toxic waste.

Galarian Variant
In the Galar region, Weezing is a dual Poison/Fairy-type Pokémon. Its appearance has changed due to absorbing polluted air from factories. It has a gray body with the skull, crossbones, and ring changed to the colour yellow. Both heads have a hat-like tube located on top of them that constantly releases purified air. Five green puffs of poison gas clouds can be seen floating around it. The larger head has a cloud-like moustache, while the smaller head has clouds on its face in the shape of eyebrows and a beard.

Galarian Weezing consumes pollutants from the air around it and digests them, releasing purified air as its excrement. The toxins within Weezing's body are accumulated into poison gas clouds that leak and drift around it. The gas is Weezing's best weapon in battle, being potent enough to stun and immobilize an opponent with just a whiff. Galarian Weezing preys on Trubbish for the fumes it produces.

Abilities

 * Poison Gas - Weezing expels toxic fumes from its body that will poison anyone who inhales them.
 * Clear Smog - Weezing releases a gas that not only inflicts damage, but negates whatever altered stats the opponent has.
 * Sludge Bomb - Weezing throws up a large ball of toxic slime that explodes on impact, dealing moderate damage as well as poisoning the target.
 * Belch - Immediately after eating, Weezing lets out a powerful belch. The stench is so pungent that it greatly reduces the opposing Pokémon's vitality.
 * Strange Steam - The Galarian Weezing expels a blast of vapour that not only deals heavy damage, but leaves the opponent dazed and confused.