You cant. You have to catch a gastly then envolve it to haunter then trade with someone and trade back haunter will envolve to gengar!
yeah you can catch wild gengar and rotom in there!:)
to my knowledge you cant. some one has to trade you a hounter. the hounter will immediately evolve into gengar. you can just trade it between two of your own games, ifyou have access to two DSes
if you find a gastly in lavender tower after you get silph scope you can find a gastly and catch it and it will level up evolve into haunter then level it up and it evolves into gengar! wrong! the correct way is to catch gastly in lavender town in the place with all the graves. then evolve it into haunter (i think at lvl 22, but im not sure) then trade it and it evolves, then you can trade it back and you have gengar.
Same as Pokemon Diamnd/Pearl. And heres a guy doing it on Pokemon diamond: http://www.youtube.com/watch?v=9xMVXUn5whI
I do not know where to get it. But if you trade a HAUNTER to someone, then once the trade is done it will instantly evolve. That's the easiest way.
Gengar can only be obtained by trading a Haunter.
There is no place that you can catch a Gengar and he can only be obtained by evolving Haunter via trade.
You'll need to trade for a Haunter or a Gengar in the GTS or from someone.
you can't catch a gengar. you catch a haunter then trade it so it evolves. make sure its not holding an everstone. ;)
evolve it by trading it with another player
You cant catch Gengar in there, only Gastly and the Rotom in the tv.
Gengar is never a wild Pokémon and therefore is not catchable. The only way you can obtain it is to trade a Haunter.
You can't in order to get a gengar go to the Pokemon tower in lavender town and catch a ghastly then trade it to a friend or another gba and trade it back so it will evolve into a Gengar.
You cant catch it. You can catch a gastly, raise it into a haunter. to make it a gengar, you have to trade it and trade it back
None yet. POKEMON PLATINUM, it is out in Jp
To catch relicanth use Hypnosis by Gengar and get lots of Dive Balls
catch a haunter and trade it to someone then it will evolve but remember to ask them to trade it back