Gastly

Gastly is a Ghost/Poison-type Pokémon introduced in Generation I, known for its gaseous form and mischievous nature. As the first stage in a three-part evolution line, it evolves into Haunter and then into the iconic Gengar. Gastly is often found in dark, abandoned places like old buildings, cemeteries, and caves, where it enjoys scaring people and other Pokémon. Its body is composed almost entirely of poisonous gas, allowing it to float freely and phase through solid objects. In the Pokémon anime, Gastly is frequently portrayed as a playful but sometimes sinister entity, often causing trouble with its gaseous abilities and unsettling laughter. Its unique composition makes it immune to many physical attacks, a trait reflected in its Ghost typing. Gastly's design, inspired by traditional Japanese yokai and Western ghosts, has cemented its place as one of the most recognizable and beloved Ghost-type Pokémon, embodying the spooky and mysterious side of the Pokémon world. Its evolution line is a staple in many trainers' teams due to its strong Special Attack and Speed stats in the video games.