Amnesia Psyduck
Get all 151 Pokémon in the hall of fame.

Surfing Pikachu
To teach your Pikachu Surf, unlock Round 2. Then, get up to the Masterball setting on either the Poké Cup or Prime Cup (in Round 2). Complete the Masterball setting with Pikachu as one of your active Pokémon each round (he must be one of the three you choose to battle with). If you lose, you cannot continue (it must be a pure win and the Pikachu may not be part of a registered team or a "Rental"). If you succeed, the game will congratulate you and ask if you would like to replace one of Pikachu's moves with Surf. Select "Yes", then choose the move to be forgotten. The Pikachu will now pull out a surfboard and ride the wave whenever Surf is used.

Talking Pikachu
Upload Pikachu from the yellow version of the game to Pokémon Stadium. When battling, Pikachu will say its name and have different motions for certain moves. Note: You must go to battle for this to work. Do not register Pikachu.

Surfing Raichu
Get a Raichu that knows SURF (as seen by Surge's Raichu). It will put its tail under itself and use it as a surfboard.

Mew
Mew will become playable, as a "Rental" Pokémon, in the Round 2 version of the game. He can only be played in the Prime Cup tournament, Gym Leader Castle, Free Battle, and Mewtwo Battle modes.

Mew in Prime Cup
This trick requires a Game Boy Game Shark and Pokémon Yellow. First start the game and enable the Game Shark code to catch Mew. Put it first in your line-up, then save the game. Go to the Game Shark screen and enable the code for the first Pokémon in your line-up to be any desired Pokémon. Check your stats and it should display your selected Pokémon's picture, but with Mew's name and information. Save the game. Place the game in the transfer pak and go to the Pokémon Stadium building. When prompted to select Pokémon, choose the one that was Mew. When you start the match, the Pokémon will be Mew.

Mewtwo Battle
Successfully complete all Cups in Stadium mode, and defeat all opponents in the Gym Leader Castle. Mewtwo is the last opponent you will face in both Round 1 and Round 2 versions of the game.

Round 2
Successfully complete the game to unlock a much harder version of the Stadium, Gym Leader Castle, and Mewtwo Battle modes.

Kids Club Hyper mode
In one player mode with three CPU controlled opponents, successfully complete "Who's the best?" five consecutive times on the hard difficulty setting within one match. Hyper will be unlocked as a new difficulty setting for CPU controlled players.

Alternate Pokémon colors
Pokémon that you upload from the Game Boy version can have alternate colors. Giving your Pokémon various nicknames will change their colors. Switch syllables, such as calling a "Mewtwo" to "Twomew" (blue color). Separate the syllables with a hyphen, such as "Mewtwo" to "Mew-two". Also try naming the Pokémon in all lower-case characters. To find out more methods, note the color of the opposing Pokémon and look at their nicknames.

Alternate title screen
Successfully complete Gym Leader Castle and Stadium modes. Then, Pikachu, Blastoise, Charizard, Venusaur and Mewtwo will appear on the title screen.

Play Pokémon faster
Successfully complete the entire Poké Cup to get a sticker on the GB Tower. This will allow you play Pokémon on the Nintendo 64 twice as fast. If you beat the Masterball in the Prime Cup, a "Superfast" setting will be unlocked in the GB Tower. The title will change to "Doduo GB Tower". Press C-Left to activate it.

Get Pokémon presents faster
Successfully complete the Gym Leader Castle. Then when you want to complete it again, go to the Gym Leader Castle, go directly to the Elite 4, and defeat your rival.

Bonus stickers
Successfully complete R-1 mode, defeat Mewtwo, complete R-2 mode, and defeat Mewtwo again. Enter the gallery screen, then hold L + R and highlight the "Print" option. Keep holding the buttons until "Print" changes to "Bonus" to access sixteen more stickers.

Start with all three beginning Pokémon
When you start a new game, you can start with all three beginning Pokémon by starting over and choosing one of them in the Game Boy Pokémon game. Then, capture a Pidgey or Rattata. Save it to the boxes on Pokémon Stadium. Repeat the steps with a different Pokémon until you get all three. You can also save and keep Pokémon from your old game that you still want before starting over.

Avoid recoil damage
If you use an attack that you know will kill the opposing Pokémon, but will hit you with the recoil, make sure that your Pokémon has at least 20 HP left. Use the attack and you will not suffer the recoil damage.

Trade without a second transfer pak
Put a box on the game, then put the Pokémon from a different game or the same one in the box. Then, go back to the lab and put the box back on the game that you are trading to, go to the box, and withdraw the Pokémon when you want or need it. Note: This also works with items.

Give Pokémon to another Game Boy pak
Place the desired Pokémon in a separate box from which you have your regular Pokémon. Transfer that box to the 64box on the Nintendo 64. Shut off the system (if you only have one transfer pak) and insert desired Game Boy pak. If you have two transfer paks, then just switch the Game Boy pak with the one you are going to trade to. Then, transfer the box with the Pokémon in it to the other Game Boy pak and you will have the Pokémon without giving one in return.

Game Shark codes without a Nintendo 64 Game Shark
The "Import" feature and import pack can be used with Game Boy Game Shark codes while playing the original game or codes designed for it.

Get Pokémon for Game Boy game
Complete one of the Gym Leader Castles of the Elite Four or your rival to get one of the following random Pokémon that can be transferred back to your Game Boy Pokémon game:

Eevee
Hitmonlee
Hitmonchan
Squirtle
Charmander
Bulbasaur
Omanyte
Kabuto

Pokémon Stadium Cup requirements
Pika Cup:
Pokémon can only be between level 15-20.

Petit Cup:
Level ranges between 25-30. There is a height requirement though. Height 6'8" limit and weight 44 pounds.

Poké Cup:
Only can use 3 Pokémon, levels 50-55. The sum of the Pokémon's levels cannot exceed 155.

Prime Cup:
Everything is legal. You can have any level, height, weight, or number of Pokémon. However, your opponents' levels are always 100.