Pokemon with Poison Gas, Smog or air-based Flying-type moves (Pokemon)
Wheezers (Dead Space)
Laila (Bondi Band)
Hideous Zippleback (Dreamworks Dragons franchise)
Snaptrapper (Dreamworks Dragons franchise)
Gazzy (Maximum Ride)
Caeser Clown (One Piece)
Kraab (Ben 10)
Stinkfly (Ben 10)
Princess Fragrance (Miraculous Ladybug); via perfume gun
Woozy Shooter (Xiaolin Showdown)
Wuzzy Bunny (Xiaolin Chronicles)
Gutrot (Ben 10) can project various gaseous elements.
Woozy Shooter (Xiaolin Showdown) can project woozy gas to makes others woozy.
The power of the Gas-Gas Fruit allows Caesar Clown (One Piece) to generate various types of gases.
Wuzzy Bunny (Xiaolin Showdown) can emit noxious gas that makes other woozy
The Hideous Zippleback (Dreamworks Dragons) is a species of dragon where one head breaths a flammable gas for the other to ignite, creating an explosion in the process.
The Snaptrapper (Dreamworks Dragons franchise) is a dragon that is able to breath a flammable mist containing methane, and can produce the smell of chocolate from their mouths to lure in potential prey.
With her perfume gun, Princess Fragrance (Miraculous Ladybug) is capable of generating a near-limitless amount of perfume with a number of different effects...
...enough to cover all of Paris in a cloud of perfume.