Gengar

Gengar (Japanese: ゲンガー Gengaa) is a /-type Pokémon introduced in Generation I.

Physiology
Gengar is a shadow-like round-bodied Pokémon with two large pointed ears and short spikes lining its back. Gengar has two red eyes and a toothy sinister smile. It has claws on its hands. Gengar stands on its two short legs, but it can Levitate as well.

Special abilities
Gengars have the ability Levitate. Levitate makes Gengar immune to -type moves. This Pokémon hides in the shadows. It is said that if Gengar is hiding, it cools the area by nearly 10°F. When there is a Full Moon, this Pokémon likes to scare people by pretending to be their shadow, then laugh at their fear. Gengars are mostly based on being mean and evil by tormenting people, hurting them and overtaking them. It can absorb any surrounding heat, leaving a sudden chill. To steal the life of its target, it slips into the prey's shadow and silently waits for an opportunity. Gengar is also able to merge with and inhabit the shadow of another being.

Evolution
Gengar is the evolved form of Haunter, by trade. It can further evolve into Mega Gengar by using its Gengarite.

Anime

 * Giant Gengar
 * Drake's Gengar
 * Morty's Gengar
 * Agatha's Gengar
 * Fantina's Gengar
 * Red's Gengar
 * Conley's Gengar
 * Lon's Gengar

Leveling
Generation VI=

Generation V=

Generation IV=

Generation III=

Generation II=

Trivia

 * Despite Gengar being able to sneak within shadows, it is unable to learn the move Shadow Sneak.
 * Despite being part -type, it cannot learn any Poison-type moves by leveling up.
 * Even though Gengar isn't levitating, it still has the ability Levitate.
 * Unlike most Pokémon, a Shiny Gengar has a small physical difference from a normal Gengar in HeartGold and SoulSilver. In said games, the spikes on a Shiny Gengar's back are shaped differently than a regular Gengar's.
 * Gengar is four inches shorter than Haunter, despite it being evolved from Haunter.
 * Mega Gengar, like Mega Alakazam, gets shorter when it Mega Evolves.
 * Gengar's Mega Stone is banned by Smogon on online battles in X/Y due to Shadow Tag and Perish Song.
 * There is a theory stating that Gengar might be the shadow of Clefairy or Clefable.
 * This is because they have a similar physical appearance, because Gengar's name originates from the term "doppelganger", and because Gengar's species is Shadow Pokémon.
 * Gengar, along with Nidorino and Jigglypuff, are the first Pokémon to appear in any Pokémon media.
 * Back in 2014 a shiny Gengar was released with the move Sludge Wave, a move Gengar normally cannot learn.

Origins
Gengar may have been based on the Oni, a creature of ancient Japanese folklore that was said to float invisibly above cities, bringing anything from a natural disaster like an earthquake to a terrible disease. It also appears to be based off a ghostly cat. Its name is possibly based off "doppelganger".