Gastly

Gastly is a mysterious, gaseous Pokémon introduced in Generation I. It is a dual-type Ghost/Poison Pokémon, known for its mischievous nature and ability to float through walls. Gastly evolves into Haunter starting at level 25, which then evolves into Gengar when traded. In the Pokémon games, Gastly is often found in dark, abandoned places like Pokémon Tower or the Old Chateau, preying on the fears of others. Its Pokedex entries consistently describe it as being composed of gas, capable of engulfing opponents. In the anime, Gastly has appeared in various episodes, often playing pranks or causing trouble, particularly in the Lavender Town arc. Its evolutionary line, especially Gengar, holds significant cultural importance as one of the original and most popular Ghost-type Pokémon, often associated with Halloween and spooky themes. Gastly's ethereal form and unsettling grin have made it a memorable figure in the Pokémon universe, embodying the spooky side of the franchise.