You'll have to restart the console.
yes at supercheats.com/pokemon heartgold action replay codes
yes you can...you make eggs in all Pokemon games
You make them breed with Ditto.
No you cannot sorry
no
You can't.
There is no best Pokemon on Pokemon HeartGold.
Okay, you make no sense. Apricorns make Pokeballs dumbo. You can't get Celebi in Heartgold.
there is no Pokemon Mansion in Heartgold.
take it to pewter museum
They are not in Pokemon HeartGold
In video games, the only version you can make your Pokemon follow you is in Pokemon yellow ( only pikachu), Pokemon heartgold, and Pokemon soulsilver