Character: Ghos (Junsaa) 2i606b

Gastly (Spirit in the Beta versions of the English language versions of Pokémon Red and Blue) is made of a very thin, gas-like substance, which grants it certain powers and weaknesses. Some say it is an other-dimensional lifeform, while others believe it is formed from toxic gas. It can sneak into any place if it so wishes thanks to the invasive properties of gas molecules. It can render itself nearly invisible and approach enemies undetected, and can envelop said enemies regardless of their size and induce sleepiness, slow poisoning through the skin, or even suffocation.

On the other hand, Gastly's negligible weight and gaseous nature make it very easy for it to be blown off or even scattered to nothingness under a strong wind (although it is presumed the molecules can regroup later). A Gastly will not appear in windy weather if it can help it, but when it finds itself threatened by a strong wind, it clusters in groups under the eaves of houses to protect itself.

Morty's Gastly was the first Pokemon sent out to battle against Ash.

Ash's Haunter de-evolved into Ash's Gastly while in the alternate world.

Gastly is apart of the Captain's Pokémon team who won the Orange Island League over 300 years ago.
The captain met his demise when a bad storm sank his pirate near Moral Island and the wreckage remained undisturbed until a couple of deep sea divers located the ship and scavenged the Orange Island League trophy which was placed in a museum.
Gastly and Haunter awakened from their Pokéballs and rose the ship above the water to search for the Orange Island trophy and replace it back inside the ship as a tribute to their late master.