you can either trade one for a medicham in the house on the left side of snowpoint city or after you beet the elite four you can go to turnback cave in senoff spring and there are tons there but keep in mind that they will be lv 50-60.
Hope this helped
You trade haunter to get gengar.
Haunter evolves when traded
Some lady in a city will trade you it but it will stay as haunter.
Haunter evolves only by trading to another game.
Actually, Haunter does evolve. Its evolves into Gengar when you trade it.
gastly, haunter, gengar
you get it over a trade.
Nothing, to evolve haunter you have to trade him...
25 into Haunter and then if u trade Haunter he evolves into Gengar
trade
turn back cave
yes