Well there is two ways i know.
1.Solceon Ruins (There will be other Pokemon too)
2.Eterna Forest (Near the entrance to eterna you see trees to cut leads into spooky house and lots of gastly r there)
Once you've gotten the Silph Scope, the ghosts will show their true forms as Pokémon, and you can catch them like any other. The only exception is the Marowak ghost near the top of the tower, which must be KO'd.
you can go to the lost tower near solaceon town... or you can go to old chateau. (you have to have a Pokemon that knows cut) old chateau is in the eterna forest.. you'll see it when you enter or exit.
Gastly evolves by leveling it up to level 25.
you need to have an upgrade and shiny stone catch normal then give shiny stone then switch with up grade.
Gastly evolves at Level 25.
The three Pokemon that are a Poison/Ghost Type are Gastly, Haunter, and Gengar that are in Pokemon Blue.
You don't need to get a gastly to evolve because you can catch haunters in Pokemon tower
Gastly is unobtainable in Pokemon Ruby. You need to trade one from Pokemon Firered or Leafgreen.
Go to lavendar town and then enter Pokemon tower in there you can find a gastly.
Gastly is found in Bellsprout Tower.
No, Gastly cannot learn to fly.
zubat, cascoon, golbat, a lot of ghost Pokemon like gastly and mistreavious.
You cannot get Gastly, Haunter, or Gengar in Pokemon Black without trading or transferring it from a previous pokemon game (i.e Platinum). However in the Pokemon Dream World, by logging into the Pokemon Global Link website, and entering the Spooky Manor area, you can get a Gastly there. if you befriend the gastly (by reaching the target scores for the minigame it offers) it will be waiting in the Tree of Dreams at the end of your session. If you have any berry to offer (which can also be found in Dream world areas, usually noted by a multicolored sparkle) gastly will be added to your friend board (which can be found in your dream home) Next, wake your pokemon that you tucked in. the next time you play your pokemon black or White version, go to the entralink and you'll be transported to the center of the Unova region. enter the forest nearby and in the forest gastly will be waiting. you'll enter a battle, you can only use your bag in which there'll be a dream ball which will catch the gastly without fail. to get the gengar, you'll have to trade haunter to either another black version or white version.
Gastly evolves to Haunter at level 25.
Gastly and Misdreavus on pearl. Gastly and Murkrow on Diamond.
Yes you can get gastly I dont no about duskull