If by 'fluffy' you mean the Pokemon flaafy, and not some other Pokemon that is unknown to me (of which there are few), it can be found in the following places at the following levels:
Route 42 -- Levels 15 +17
Route 43 -- Levels 15, 16 +17
Route 42 and Route 43! look on your pokedex!
you can get it on route 43
you can get it by getting a pichichu in pearl trade it to heartgold
In Pokemon Heartgold or gold and soulsilver or silver you can find it in viridian forest.
black stone
Confusion isn't a TM.
You can't. SoulSilver Only, unfortunately.
flaffy doesnt evolve by level it evolves when you give it a thunder stone
You can not.
In Pokémon HeartGold, you can find the 3rd Gym Leader in Goldenrod City.
You cannot find Deoxys in HeartGold, or SoulSilver. You can only get Deoxys through trading or at a Pokemon Event.
Groudon is unavailible in Pokemon heartgold trade from soulsilver to get groudon.
No, you can not get registeel in HeartGold or SoulSilver. The only way to get it, is by trading
no you can't
Mt.silver
goldenrod
in safari
You cant!
trade