There is a pokemon that you cant catch in pokemon black and white his name is Zoroark (Im just going to tell you about Zoroark). Zoroark, the illusion fox pokemon:
Type: dark ability:
Weight: 178.8 lbs.
And here’s how to catch it.
First, you need a shiny Raikou, shiny Entei and shiny Suicune. At the special event at game stop you cannot get Raikou or Entei because that dates have already passed, but Suicune is still open. He appears on Jan 31st, 2011 through Feb 6th, 2011.
Here are the rules:
1) You need to go to “mystery gift” in your pokemon diamond, pear, platinum, heart gold or soul silver version.
2) Go to game stop and turn on your ds, dsi or dsixl. Go to “mystery gift” on your pokemon game thats is for ds, dsi, or dsixl.
3) Select: “Get via wireless” and then press “yes” at the legendary trio of johto.
4) You got a shiny Suicune, Entei or Raikou.
5) After you get it, have one slot open for the shiny Suicune, Entei and Raikou.
6) Go to the pokemarket and talk to the delivery man. He will give you your shiny Suicune, Entei or Raikou. Then save your game.
7) Transfer a shiny Suicune, Entei or Raikou to pokemon black and white and find Zoroark.
That is how you catch Zoroark. He will be a disease to Suicune, Entei or Raikou. If you see one of them attack it with one of your characters. Then it will show it’s true form, a Zoroark. Then catch it with an ultra ball, but save before battling him. or maybe you might kill him he will be a disease to humans so talk to everyone you see. That is how you catch Zoroark.
I have also heard that you can get Ash’s Pikachu from the pokemon show on to your ds, dsi or dsixl. Just follow the rules of the shiny Suicune,Entei and Raikou event, but you can get Pikachu at Toys r Us. Pikachu appears from Jan 30th, 2011 through Feb 13th, 2011.