Gastly evolves at level 25.
You can't capture cloyster to get one use a water stone on shellder.
I had the same problem XD - when you enter the Victory Road, go straight until the sharp right turn, go down with rock climb, and go left under the Rope bridge thingy, their will be a trainer with both Gengar (gastly's last form) and Gardevoir, Ralt's original last form.
Gastly evolves into Haunter at Lv25.
Gastly is #92 in the national pokedex, and it is a Ghost-Poison type Pokemon.
cloyster is an water-ice type Pokemon his pokedex color is :purple he is 13 years old his pre evolved evoulution of him shellder is 4 years old his friend gastly are both very mishteve. And watch out he is very sneaky!
gengar
Cloyster evolves from Shellder by using a Water Stone on it.
Cloyster cannot evolve.
For Cloyster its basic
haunter then gastly
Get a shellder then use a water stone on it and it will evolve into a cloyster.
Gastly evolves at level 25.
Catch a shellder then use a water stone on it it will evolve into cloyster.
Gastly can learn: *Sucker Punch *Confuse Ray *Shadow Sneak *Astonish *Ominous Wind *Revenge *Taunt (TM) And others. ---Note--- To get the fully evolved form of Gastly, you have to trade. Gastly evolves into Haunter at lvl 22 or 25 depending on the game and into Gengar when traded. No held item is needed to trade. ---PokeFreak
gastly evolve on level 25
The only way that you can get a Cloyster on your Emerald game is if you trade it from FireRed or XD.