Not from the start, but if you beat the game you can. There is another way though. In a Castelia City building, on a top floor a man will ask you for a 4-word passcode to access a hidden machine. That passcode is
EVERYONE HAPPY
SIMPLE CONNECTION
If you give this to him he will let you use his relocater. Just go to the title screen and select 'relocater'. Follow the on-screen instructions.
* You cannot trade Pokemon back to an older version after trading to a new one!
rotom, basculin, cottonee, and more
You can not find an NPC to trade with, no NPC will. You have to have a friend who owns Firered or Leaf Green & trade with a REAL LIFE friend, trade back...then.....WHAT, HAUNTER IS EVOLVING!
You can't the Naga are NPC's which means they are Non-Player-Characters.
To be exact, the NPC's name is Karcasa at "The Burning Sands, Tent of the Entertainers" where the Desert Rabbits are -.-
When you are told a Pokémon has been sent to "Someone's PC" it means the Pokémon has been stored in the PC at the Pokémon Center, you are free to take Pokémon in and out of them. The "someone" is a series tradition in that your character eventually meets the NPC that created the Pokémon storage system in that game's region.
because it would ruin the whole idea of first person as the character is meant to be you so basically you answer it in your head but the npc's of course could not interact with it.
You cannot catch a Cottonee but you can trade a Petilil for one in either Nimbasa City or Driftveil City I am not sure which one. You can also trade with a friend who has Black. It is the other way around for Black.
at chapters
Ralts is unavailable in Black. There are many ways to get one to black, however. Transfer one from a Generation IV game (Diamond, Pearl, Platinum, HeartGold or SoulSilver). Trade one from White (Ralts is available via white forest if the appropriate NPC is present.)
There is no NPC who you can trade a Haunter to for a Gengar in Pokemon Crystal. To get Gengar you will need to trade with another player or a copy of Pokemon Gold, Silver or Crystal.
Genesect is a legendary Pokémon which means no NPC trainers will be holding one.
an npc Pokemon is a Non-Playable-Charecter. if your realy stupid, a Pokemon that you cant use.
For wild, catchable ones, it is Cottonee, Gothita and Vullaby. Cottonee however can be traded from an NPC in Nacrene City. Then as well as these, the legendary Pokemon Tornadus and Reshiram are Black-exclusive.
There is no legendary Pokemon in Challenger's Cave. One NPC mentions that one Pokemon was raised there. It is most likely to be Keldeo, but it does not live there any more.
In Pokemon Diamond TM07 can be found on Route 217. You can also trade 10 Green Shards to an NPC on Route 212 for a copy of TM 07.
There is supposed to be some sort of NPC that will trade you a graveller for one of your pokemon. I think he's in the big shopping mall building, but I'm not completely certain, as I haven't played Yellow in a long time.
You cannot make your flag black. It is a barbarian city, or NPC (non player city). NPC's have black flags
You have to max out the partners--when you max out the partner, you get an item from one of the NPCs that you can trade to another NPC for a summoning item. This is actually in the forum guide.