Trade it to to somebody else
Trade Haunter with any Pokemon to make it evolve!
Haunter evolves into Gengar via Trading.
Haunter doesn't evolve at any level to evolve your haunter you need to do a link trade with a friend and he he will then evolve
You evolve it into Haunter at Level 25. To evolve Haunter into a Gengar, you need to trade it.
You have to trade to another game to make it evolve.
You'll need to trade for a Haunter in order for it to evolve into Gengar.
you must trade your haunter to evolve it into a gengar
haunter has to be traded to evlove haunter evolve into gengar in level 42
OF COURSE!! you'll need to trade an haunter to a friend, and haunter will evolve TO GENGAR
You have to trade haunter to a friend to evolve it.
Haunter will only evolve through trade.
you have to evolve him into a haunter first then trade haunter to someone and it will evolve