>>47300127Dude that wasn't original for the anime. That's the secret Poke'mon RainFearow. To find RainFearow you need to have all you're PC boxes filled with Fearows and have a team full of level 100 Fearows and a Pikachu. You can trade your other Poke'mon to another game and get some Fearow from there so you don't have to release your Mewtwo and stuff. Here's how you find RainFearow:
1) Have boxes full of Fearows
2) Have a Pikachu in the first slot of your party, followed by 5 level 100 Fearows
3) Fly to Pallet Town and talk to Prof. Oak
4) Fly to Cinnabar Island and go to Poke'mon Mansion and read all the diaries
5) Surf at the side of Cinnabar Island and you should encounter a Spearow
6) Fly to Cerulean and go to Bill's house and talk to him
7)He'll tell you he heard about a rare Pokémon by Viridian City
8) Fly to Viridian City and head to Route 1
9) You'll see a bird standing in the grass. Talk too it (make sure you save first!)
10) Battle RainFearow and catch it.
I heard that they did this for the anime because it has different colored Poke'mon in it like the Rainbow Fearow in episode 1 and pink Butterfree.