Haunter evolves only by trading to another game.
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.
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
turn back cave
trade
yes
A Haunter has to be traded to evolve. You have to trade it without it holding an Everstone and it will evolve into a Gengar. The Everstone will stop the evolution process.