| Pokedex Entries: |
| Red | Almost invisible, this gaseous Pokémon cloaks the target and puts it to sleep without notice. |
| Blue |
| Yellow | Said to appear in decrepit, deserted buildings. It has no real shape as it appears to be made of a gas. |
| Gold | With its gas-like body, it can sneak into any place it desires. However, it can be blown away by wind. |
| Silver | Its thin body is made of gas. It can envelop an opponent of an size and cause suffocation. |
| Crystal | It wraps its opponent in its gas-like body, slowly weakening its prey by poisoning it through the skin. |
| Ruby | GASTLY is largely composed of gaseous matter. When exposed to a strong wind, the gaseous body quickly dwindles away. Groups of this POKéMON cluster under the eaves of houses to escape the ravages of wind. |
| Sapphire |
| Emerald | When exposed to a strong wind, a GASTLY's gaseous body quickly dwindles away. They cluster under the eaves of houses to escape the ravages of wind. |
| FireRed | A being that exists as a thin gas. It can topple an Indian elephant by enveloping the prey in two seconds. |
| LeafGreen | Almost invisible, this gaseous Pokémon cloaks the target and puts it to sleep without notice. |
| Diamond | This Pokemon's body is 95% made up of gases, which are blown away by strong gusts of wind. |
| Pearl | A Pokemon born from poison gases. It defeats even the largest foes by enveloping them in gas. |
| Platinum | Born from gases, anyone would faint if engulfed by its gaseous body, which contains poison. |
| Stadium 1 | Made of a thin, gas-like substance that induces fainting if you get enshrouded in it. Will not appear if it is very windy. |
| Stadium 2 | With its gas-like body, it can sneak into any place it desires. However, it can be blown away by wind. |
| TCG | Gastly: Its gas-like body allows it to enter almost anywhere, but it is vulnerable to high winds. |
