no just buy it
After giving the machine part to the power plant ( the machine part is in the cerulean city gym in the water) go to saffron city and go into the copycats house( near the magnet train) then talk to the copycat she will ask you to get her doll. Go to vermillion city and go in the Pokemon fan club inside a guy is hanging out with a clefairy, its a doll, talk to the guy and he will give it to you. Finally deliver the doll to the copycat and you have the rail pass.
If given to Nidorino, Nidorina, Clefairy and Jigglypuff it will evolve each to Nidoking, Nidoqueen, Clefable and Wigglytuff.
The Pokémon who you can stroll with in Amity Square in Pokémon Diamond (and Pearl) are Pikachu, Clefairy, Jigglypuff, Psyduck, Torchic, Shroomish, Skitty, Pachirisu, Drifloon, Buneary and Happiny.
Go to a big blue house in Saffron City and talk to the little girl copycat upstairs and she will say that she lost her favorite poke doll clefairy. Then go to Vermilon City and go into the poke fan club and talk to the fat guy sitting at the table and he give the poke doll and go out and the league champ of the Hoen region will talk to you and he will say that latias has flew out of hoen and into Kanto. Then return the poke doll to copycat and she will give you the magnet train pass.
It attracts a ledendary pokemon.
Clefairy......
Suwoodoo learns it and jigglypuff and clefairy
You will find it on the table at the Pokemon Fan Club. Talk to the person at the table and tell him about Copycat lesing her Clefairy Doll. He wil give it to you. after you return it to Copycat in Saffron City, she will give you a pass for the Magnet Train.
First you need ticket from Saffron City by giving Copycat girl her Clefairy Doll in Fan Club in Vermillion City.
go to mount moon and walk around
When you receive the clefairy doll off the guy in the fan club Steven from Hoenn will ask you and show it to you then it will be in the wild like suicune. etc Latias and Latios will vary between Soul Silver And Heart Gold. Good Luck!
Answering from memory, there is a girl known as the copycat girl who lost her clefairy doll. and you have to go get it and give it to her. I think its found in a Pokemon fan club or something. sorry if my information is not 100% correct.
It's Darkrai. You can't get him in Heart Gold.
Pokemon Heart gold is different from Pokemon Gold cuz heart gold has better graphics new Pokemon and new events
In Pokemon Gold, the Copycat Girl will give the player the rail pass when they give her a doll. The doll can be obtained from a member of the Pokemon Fan Club in Vermillion City.
Talk with the guy in the fanclub in Vermilion. He has the doll and will give it to you.
Whitney uses Clefairy and Miltank in Pokémon Gold/Silver/Crystal/HeartGold/SoulSilver and in the anime she has a Nidorina, a Clefairy and a Miltank.