Gastly

Gastly (Japanese: ゴース Gousu) is a /-type Pokémon introduced in Generation I.

Physiology
Gastly's appearance consists of a dark sphere (its "head") surrounded by a light purple gas. Gastly have big, white eyes and a mouth with a pair of fangs in it.

Behavior
Due to having a body made of gas, Gastly can slip into any place it wants.[64] However, Gastly's body will dwindle away when exposed to a strong wind. Because of this, groups of them shall gather under the eaves of houses to prevent being blown away. They are also proficient at sneaking up on unsuspecting prey and putting it to sleep or poisoning it through its skin. As Gastly's body is blown away by wind Gastly live in old, dilapidated buildings, and can also be found at cemeteries.

Special abilities
Gastly have the ability Levitate, which allows it to make all -type moves to miss. Gastly is made of a very thin, gas-like substance, which grants it certain powers and weaknesses. It can sneak into any place if it so wishes thanks to the invasive properties of gas molecules. It can also render itself nearly invisible and approach enemies undetected, and can envelop said enemies regardless of their size.

Evolution
Gastly evolves into Haunter at level 25.

Leveling
Generation VI=

Generation V=

Generation IV=

Generation III=

Generation II=

Generation I=

Anime
In the anime, Gastly first appeared in The Ghost of Maiden's Peak. This Gastly had the ability to talk and shape-shift. He kept posing himself as the spirit of the woman which legend said turned to stone after many years of waiting for her love to return to her. Gastly kept on toying with the minds of young men. The first time a regular Gastly appeared was in The Tower of Terror. Ash and his friends went to Lavender Town in search of a -type Pokémon to aid Ash in defeating Sabrina. Morty used a Gastly to battle Ash in from Ghost to Ghost. A pair of Gastly were among a group of Ghost Pokémon living in an abandoned mine in Fear Factor Phony. The Ghost Pokémon couldn't stand the partying Pokémon that lived in the nearby town, so they created a Haunter-like illusion to scare everyone away.
 * Officer Jenny's Gastly
 * Captain's Gastly
 * Morty's Gastly
 * Lon's Gastly

Manga
In the Pokémon Adventures manga, Gastly first appears possessing the corpses of dead Pokémon in Pokémon Tower. Red's Bulbasaur manages to defeat it by sucking up the surrounding air with its bulb, along with Gastly's gaseous form, and expelling it in a Solar Beam. Gastly also forms as part of the Ghost-type army Agatha sends out to attack the Gym Leaders. The Masked Man also used a Gastly in his team to capture Celebi, due to its type advantage. It was purposed to possess intruders that entered the Ilex Forest. Later, during the fight at the Indigo Stadium, it took out Suicune using its Curse technique, locking Suicune and Misty inside Suicune's crystal wall. It was later defeated by Eusine's Haunter.

Trivia

 * In one of its Pokédex entries, an Indian elephant is mentioned, which is interesting because in the Pokémon World such animals don't exist. An Indian elephant is also mentioned in one of the Pokedex entries for Raichu.
 * Its name is based on the word "ghastly".
 * Gastly and its evolved forms are the first and only / type Pokémon.

Gallery
고오스 (포켓몬)