Gastly and Haunter possess its Trainer from a Poke-ball by trying everything to succeed.
Gastly evolves into Haunter at Lv25.
haunter then gastly
Gastly evolves into Haunter at level 25, then trade it and it will evolve again into Gengar.
Gastly evolves into Haunter once it reaches level 25 or higher.
Gastly evolves to Haunter at lv25. And Haunter evolves to Gengar after trading.
yes, and gengar evolves from haunter after it is traded.
Gastly evolves to Haunter at level 25. Then, Haunter evolves into Gengar by being traded.
Gastly evolves to Haunter at level 25.
Gastly evolves at level 20 into Haunter
Gastly Lvl.25>Haunter Trade>Gengar
To evolve Gastly into Haunter just get it up to level 25.
Gastly evolves at level 22 then Haunter evolves by trading it.