Gastly

Gastly (Japanese: ゴース Goosu) is a /-type Pokémon introduced in Generation I. It evolves into Haunter starting at level 25, which evolves into Gengar when traded.

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

Characteristics
Due to having a body made of gas, Gastly can slip into any place it wants. However, Gastly's body will dwindle away when exposed to a strong wind. It can also render itself nearly invisible and approach enemies undetected, and can envelop said enemies, regardless of their size.

Habitat
Due to the fact that Gastly's body can be blown away by strong wind, they gather under the eaves of houses in order to escape it.

By leveling up
Generation VI=

Generation V=

Generation IV=

Generation III=

Generation II=

Generation I=

In the anime

 * Gastly (IL020)
 * Gastly (IL023)
 * Captain's Gastly
 * Morty's Gastly
 * Lon's Gastly

Trivia

 * In one of its Pokédex entries, an Indian elephant is mentioned, which contradicts knowledge of the Pokémon World as such animals don't exist. An Indian elephant is also mentioned in one of the Pokédex entries for Raichu.
 * Its name is based on the word "ghastly".
 * In The Ghost of Maiden's Peak, Gastly happens to hate sunlight.
 * This is due to fact that it's a - type Pokémon.
 * Gastly and its evolved forms are the first and only /-type Pokémon.

Gallery
고오스 (포켓몬)