it has to level up
Gastly evolves into Haunter at level 25, then trade it and it will evolve again into Gengar.
haunter then gastly
Gastly evolves into Haunter at Lv25.
To evolve Gastly into Haunter just get it up to level 25.
You evolve it into Haunter at Level 25. To evolve Haunter into a Gengar, you need to trade it.
you have to evolve him into a haunter first then trade haunter to someone and it will evolve
In order to evolve Haunter, u have to trade and it will evolve into a Gengar.
yes, and gengar evolves from haunter after it is traded.
Gastly evolves into Haunter once it reaches level 25 or higher.
Gastly evolves to Haunter at level 25.
Gastly evolves to Haunter at lv25. And Haunter evolves to Gengar after trading.
It evolves at Lv25.