Gastly is a dual type Ghost and Poison Pokemon introduced in Generation I. It evolves into Haunter starting at level 25, which evolves into Gengar when traded. Take a look below for 26 fascinating and interesting facts about Gastly.

1. Gastly has no true form, due to 95% of its body being poisonous gas. However, it consistently appears as a black, spherical Pokémon surrounded by a purple haze.

2. It has a wide, pink mouth with two visible fangs.

3. Though its eyes seem to extend past its round body, visible eyelids surround them.

4. It produces a faint, sweet smell.

5. The toxic gas surrounding the main body can induce fainting and suffocation, and it is capable of enshrouding an enemy of any size.

6. Its gaseous form makes it one of the lightest Pokémon tying with Haunter, Flabébé, Cosmog, and Kartana.

7. The anime suggests that Gastly has a playful personality, often frightening and playing pranks on people for fun. However, it has shown a willingness to preserve or pass on the memories of departed humans.

8. It has further been shown changing form and creating illusions, and it is capable of phasing through solid objects and forming tangible hands out of its gasses.

9. Gastly can be found in caves, but the anime has shown it living in old, dilapidated buildings, as well.

10. It will dwindle away when exposed to strong winds, so groups cluster under house eaves to escape the wind.

11. It may also cause flickering lights in abandoned houses.

12. In the past, Night Shade was its signature move.

13. In the Pokémon Red and Blue beta, Gastly’s prototype name was “Spirit”.

14. No other Pokémon have the same type combination as Gastly and its evolved forms.

15. Due to its unique type combination, Gastly and its evolutionary relatives are the only Poison-type Pokémon that are weak against Dark-type moves.

16. Despite all of them being Poison-type Pokémon, Gastly and its evolutionary family were not able to learn Poison-type moves by leveling up prior to Pokémon: Let’s Go, Pikachu! and Let’s Go, Eevee!.

17. Gastly is tied with Venipede for the lowest HP of all Poison-type Pokémon.

18. Gastly is also tied with Weedle for the lowest Defense of all Poison-type Pokémon.

19. Gastly has the lowest base Defense of all Ghost-type Pokémon.

20. Gastly seems to be based on general ghosts and spirits as depicted by cartoons, or even a will-o’-the-wisp.

21. It may also have been based on the Japanese yōkai sōgen bi, the decapitated head of a monk whose head is doomed to wander the Earth, consumed by fire.

22. Its Poison type is most likely a reference to poisonous or polluted gases.

23. Gastly may be a combination of gas and ghastly (like a ghost; dreadfully frightening).

24. Gastly debuted 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 2,000 years of waiting for her love to return to her. As the ghost of the maiden, Gastly kept on toying with the minds of young men.

25. A Gastly appeared in The Tower of Terror. Ash and his friends went to Lavender Town in search of a Ghost-type Pokémon to aid Ash in defeating Sabrina. It reappeared in a flashback in the following episode.

26. A Gastly appeared in Pikachu Re-volts, under the ownership of an Officer Jenny. It appeared to be the only Pokémon not affected by the Psychic wave caused by Butch and Cassidy’s Drowzee. It was seen outside of its Poké Ball.