Weezing

Weezing, known in Japan as Matadogas  is a poison-type Pokémon that was introduced in Generation I. It evolves from Koffing starting at level 35. It is one of the Pokémon that can be released from a Poké Ball in Super Smash Flash 2.

Pokémon description
Weezing is a purple colored Pokémon known to be formed of two heads of different sizes, in which they are connected by a tube. The right head has a light yellow circle on its head and two teeth in each corner of its mouth, while the left head has two flat teeth in its upper jaw, two pointed teeth from its lower jaw and a cream-colored skull-and-crossbones marking on its head. Weezing has holes in both heads, which release different gases in each head that mix by inflating one head and deflating the other and turning the Pokémon even more toxic. Also, probably due to gases lighter than air, Weezing can hover in midair and its gases can be used to make top-grade perfume by diluting them to the highest level. It lives in urban areas and feeds on the dust, microorganisms and especially gases emitted by garbage during the night, when the people are asleep.

In Super Smash Flash 2
As stated above, Weezing can be released from a Poké Ball. Once it is out, Weezing executes the move Smog, letting a cloud of gas out of the holes in its body. Unlike its pre-evolution's similar use of Smokescreen, if an opponent makes contact with the gas then they will take damage and low knockback, having the possibility of getting stuck in the center of Weezing's attack and being damaged until it disappears.

Trivia

 * As both Koffing and Weezing appear in SSF2, this marks the only time a complete evolutionary line can be released from Poké Balls in the game that are no alternate variants of a Pokémon using the same move, unlike the Porygon's evolutionary line.