get an everstone.
You get pupitar by evolving larvitar.
L.v 22
You'll need to trade for it, because evolving Feebas will be impossible in Pokemon HeartGold and SoulSilver.
To Stop Evolution:Tap the B Button Repeatedly until Evolution stops (While Evolving)Make your Pokemon hold an Everstone (Does not Evolve while Hold)Note: Trading Pokemon that Evolve can not be stopped.
To keep your Pichu from evolving, give it an Everstone. It will not evolve until you take the Everstone off of it.
Azumarill doesn't evolve according to level in Pokémon HeartGold because it's not capable of evolving at all.
If you keep it from evolving it can (depending on the pokemon) learn more moves that it wouldn't learn if it evolved. So to answer your question people who want those moves.
get a haunter by evolving gastly then trade to a friend and trade back and you have a gengar hope this info helps :-)
You can only obtain hitmonlee by evolving tyrogue. Tyrogue is obtained in Mt. Mortar. Source: Bulbapedia
Keep walking with them, and your friendship with them will increase.
you keep on battling the gyms
keep trading Pokemon with friends and train all your Pokemon to the stage where they stop evolving