Pokemon Yellow Version: Special Pikachu Edition Cheats

Use the Pikachu from your Pokemon Yellow in every match in the Tournament mode of Pokemon Stadium. Pikachu should learn Surf. Now go south of Fuschia City and into the house at the beach. Talk to the man inside. Make sure Pikachu is in your party. You should be able to play a mini-game.

Once you've obtained the HM Cut you can use it to teach some of your pokemon the attack of the same name.
This ability now cannot only be used to cut down certain trees but also to get rid of any grass so you don't have to bother with any random encounters.
When saving and loading or leaving and reentering the area you used cut in, the grass will have returned.

When you first start your game, you will have 1 potion in your pc that's in your room. Get it out. Continue playing the game untill you get Pikachu but haven't battled Gary's Eevee yet. Use the potion on Pikachu 5 times (even though it won't have any effect). Fight Gary and WIN. After the battle, when your Pikachu comes out of the Pokeball. He will like you.

Complete your Pokedex (Mew is optional) and visit the game designer in the Celadon Mansion. He will give you a diploma as a reward.